Ensure amazon-private-ip fixes string values

The "ssh_private_ip" key works with either boolean values or string
representations of booleans. The fixer errors when the value is defined
as, for example, "true" (with quotation marks). This commit will attempt
to convert the string into a bool when necessary to ensure this case is
handled.

Signed-off-by: Brendan Devenney <brendan.devenney@cloudreach.com>

fix/fixer_amazon_private_ip.go

@@ -2,6 +2,7 @@ package fix
 
 import (
 	"log"
+	"strconv"
 	"strings"
 
 	"github.com/mitchellh/mapstructure"
@@ -49,8 +50,12 @@ func (FixerAmazonPrivateIP) Fix(input map[string]interface{}) (map[string]interf
 		}
 		privateIP, ok := privateIPi.(bool)
 		if !ok {
-			log.Fatalf("Wrong type for ssh_private_ip")
-			continue
+			var err error
+			privateIP, err = strconv.ParseBool(privateIPi.(string))
+			if err != nil {
+				log.Fatalf("Wrong type for ssh_private_ip")
+				continue
+			}
 		}
 
 		delete(builder, "ssh_private_ip")

fix/fixer_amazon_private_ip_test.go

@@ -39,6 +39,19 @@ func TestFixerAmazonPrivateIP(t *testing.T) {
 				"ssh_interface": "private_ip",
 			},
 		},
+
+		// ssh_private_ip specified as string
+		{
+			Input: map[string]interface{}{
+				"type":           "amazon-ebs",
+				"ssh_private_ip": "true",
+			},
+
+			Expected: map[string]interface{}{
+				"type":          "amazon-ebs",
+				"ssh_interface": "private_ip",
+			},
+		},
 	}
 
 	for _, tc := range cases {