packer_test: rename mini_plugin to plugin_tester

Since the tester plugin used for blackbox testing is called
packer-plugin-tester, we rename the directory it's stored in to
plugin_tester.

packer_test/plugin_test.go

@@ -129,10 +129,10 @@ func BuildSimplePlugin(versionString string, t *testing.T) string {
 		t.Fatalf("failed to compile plugin binary: %s", err)
 	}
 
-	miniPluginDir := filepath.Join(testDir, "mini_plugin")
+	testerPluginDir := filepath.Join(testDir, "plugin_tester")
 	outBin := filepath.Join(PluginBinaryDir(), BinaryName(v))
 
-	compileCommand := exec.Command("go", "build", "-C", miniPluginDir, "-o", outBin, "-ldflags", LDFlags(v), ".")
+	compileCommand := exec.Command("go", "build", "-C", testerPluginDir, "-o", outBin, "-ldflags", LDFlags(v), ".")
 	logs, err := compileCommand.CombinedOutput()
 	if err != nil {
 		t.Fatalf("failed to compile plugin binary: %s\ncompiler logs: %s", err, logs)

packer_test/suite_test.go

@@ -25,8 +25,8 @@ type PackerTestSuite struct {
 func buildPluginVersion(waitgroup *sync.WaitGroup, versionString string, t *testing.T) {
 	waitgroup.Add(1)
 	go func() {
+		defer waitgroup.Done()
 		BuildSimplePlugin(versionString, t)
-		waitgroup.Done()
 	}()
 }