provider/aws: Fix Cloudwatch Log acceptance tests

Fixes `aws_cloudwatch_log_group` and `aws_cloudwatch_log_metric_filter` acceptance tests

```
$ make testacc TEST=./builtin/providers/aws TESTARGS='-run=TestAccAWSCloudWatchLogMetricFilter_basic'
==> Checking that code complies with gofmt requirements...
go generate $(go list ./... | grep -v /terraform/vendor/)
2017/01/31 12:01:05 Generated command/internal_plugin_list.go
TF_ACC=1 go test ./builtin/providers/aws -v -run=TestAccAWSCloudWatchLogMetricFilter_basic -timeout 120m
=== RUN   TestAccAWSCloudWatchLogMetricFilter_basic
--- PASS: TestAccAWSCloudWatchLogMetricFilter_basic (27.36s)
PASS
ok      github.com/hashicorp/terraform/builtin/providers/aws    27.390s
```

```
$ make testacc TEST=./builtin/providers/aws TESTARGS='-run=TestAccAWSCloudWatchLogGroup_multiple'
==> Checking that code complies with gofmt requirements...
go generate $(go list ./... | grep -v /terraform/vendor/)
2017/01/31 12:03:18 Generated command/internal_plugin_list.go
TF_ACC=1 go test ./builtin/providers/aws -v -run=TestAccAWSCloudWatchLogGroup_multiple -timeout 120m
=== RUN   TestAccAWSCloudWatchLogGroup_multiple
--- PASS: TestAccAWSCloudWatchLogGroup_multiple (16.39s)
PASS
ok      github.com/hashicorp/terraform/builtin/providers/aws    16.422s
```

builtin/providers/aws/resource_aws_cloudwatch_log_group_test.go

@@ -254,5 +254,5 @@ resource "aws_cloudwatch_log_group" "charlie" {
     name = "foo-bar-%d"
     retention_in_days = 3653
 }
-`, rInt, rInt, rInt)
+`, rInt, rInt+1, rInt+2)
 }

builtin/providers/aws/resource_aws_cloudwatch_log_metric_filter_test.go

@@ -6,27 +6,29 @@ import (
 
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/service/cloudwatchlogs"
+	"github.com/hashicorp/terraform/helper/acctest"
 	"github.com/hashicorp/terraform/helper/resource"
 	"github.com/hashicorp/terraform/terraform"
 )
 
 func TestAccAWSCloudWatchLogMetricFilter_basic(t *testing.T) {
 	var mf cloudwatchlogs.MetricFilter
+	rInt := acctest.RandInt()
 
 	resource.Test(t, resource.TestCase{
 		PreCheck:     func() { testAccPreCheck(t) },
 		Providers:    testAccProviders,
 		CheckDestroy: testAccCheckAWSCloudWatchLogMetricFilterDestroy,
 		Steps: []resource.TestStep{
-			resource.TestStep{
-				Config: testAccAWSCloudWatchLogMetricFilterConfig,
+			{
+				Config: testAccAWSCloudWatchLogMetricFilterConfig(rInt),
 				Check: resource.ComposeTestCheckFunc(
 					testAccCheckCloudWatchLogMetricFilterExists("aws_cloudwatch_log_metric_filter.foobar", &mf),
-					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "name", "MyAppAccessCount"),
-					testAccCheckCloudWatchLogMetricFilterName(&mf, "MyAppAccessCount"),
+					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "name", fmt.Sprintf("MyAppAccessCount-%d", rInt)),
+					testAccCheckCloudWatchLogMetricFilterName(&mf, fmt.Sprintf("MyAppAccessCount-%d", rInt)),
 					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "pattern", ""),
 					testAccCheckCloudWatchLogMetricFilterPattern(&mf, ""),
-					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "log_group_name", "MyApp/access.log"),
+					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "log_group_name", fmt.Sprintf("MyApp/access-%d.log", rInt)),
 					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "metric_transformation.0.name", "EventCount"),
 					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "metric_transformation.0.namespace", "YourNamespace"),
 					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "metric_transformation.0.value", "1"),
@@ -37,15 +39,15 @@ func TestAccAWSCloudWatchLogMetricFilter_basic(t *testing.T) {
 					}),
 				),
 			},
-			resource.TestStep{
-				Config: testAccAWSCloudWatchLogMetricFilterConfigModified,
+			{
+				Config: testAccAWSCloudWatchLogMetricFilterConfigModified(rInt),
 				Check: resource.ComposeTestCheckFunc(
 					testAccCheckCloudWatchLogMetricFilterExists("aws_cloudwatch_log_metric_filter.foobar", &mf),
-					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "name", "MyAppAccessCount"),
-					testAccCheckCloudWatchLogMetricFilterName(&mf, "MyAppAccessCount"),
+					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "name", fmt.Sprintf("MyAppAccessCount-%d", rInt)),
+					testAccCheckCloudWatchLogMetricFilterName(&mf, fmt.Sprintf("MyAppAccessCount-%d", rInt)),
 					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "pattern", "{ $.errorCode = \"AccessDenied\" }"),
 					testAccCheckCloudWatchLogMetricFilterPattern(&mf, "{ $.errorCode = \"AccessDenied\" }"),
-					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "log_group_name", "MyApp/access.log"),
+					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "log_group_name", fmt.Sprintf("MyApp/access-%d.log", rInt)),
 					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "metric_transformation.0.name", "AccessDeniedCount"),
 					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "metric_transformation.0.namespace", "MyNamespace"),
 					resource.TestCheckResourceAttr("aws_cloudwatch_log_metric_filter.foobar", "metric_transformation.0.value", "2"),
@@ -146,9 +148,10 @@ func testAccCheckAWSCloudWatchLogMetricFilterDestroy(s *terraform.State) error {
 	return nil
 }
 
-var testAccAWSCloudWatchLogMetricFilterConfig = `
+func testAccAWSCloudWatchLogMetricFilterConfig(rInt int) string {
+	return fmt.Sprintf(`
 resource "aws_cloudwatch_log_metric_filter" "foobar" {
-  name = "MyAppAccessCount"
+  name = "MyAppAccessCount-%d"
   pattern = ""
   log_group_name = "${aws_cloudwatch_log_group.dada.name}"
 
@@ -160,13 +163,15 @@ resource "aws_cloudwatch_log_metric_filter" "foobar" {
 }
 
 resource "aws_cloudwatch_log_group" "dada" {
-	name = "MyApp/access.log"
+	name = "MyApp/access-%d.log"
+}
+`, rInt, rInt)
 }
-`
 
-var testAccAWSCloudWatchLogMetricFilterConfigModified = `
+func testAccAWSCloudWatchLogMetricFilterConfigModified(rInt int) string {
+	return fmt.Sprintf(`
 resource "aws_cloudwatch_log_metric_filter" "foobar" {
-  name = "MyAppAccessCount"
+  name = "MyAppAccessCount-%d"
   pattern = <<PATTERN
 { $.errorCode = "AccessDenied" }
 PATTERN
@@ -180,6 +185,7 @@ PATTERN
 }
 
 resource "aws_cloudwatch_log_group" "dada" {
-	name = "MyApp/access.log"
+	name = "MyApp/access-%d.log"
+}
+`, rInt, rInt)
 }
-`