Add missing test project in TestMappings

Author: azdevxps

TestMappings.json

@@ -15,7 +15,8 @@
     ".\\src\\ResourceManager\\AnalysisServices\\Commands.AnalysisServices.Test\\bin\\Debug\\Microsoft.Azure.Commands.AnalysisServices.Test.dll"
   ],
   "src/ResourceManager/ApiManagement/": [
-    ".\\src\\ResourceManager\\ApiManagement\\Commands.ApiManagement.Test\\bin\\Debug\\Microsoft.Azure.Commands.ApiManagement.Test.dll"
+    ".\\src\\ResourceManager\\ApiManagement\\Commands.ApiManagement.Test\\bin\\Debug\\Microsoft.Azure.Commands.ApiManagement.Test.dll",
+    ".\\src\\ResourceManager\\ApiManagement\\Commands.ApiManagement.ServiceManagement.Test\\bin\\Debug\\Microsoft.Azure.Commands.ApiManagement.ServiceManagement.Test.dll"
   ],
   "src/ResourceManager/ApplicationInsights/": [
     ".\\src\\ResourceManager\\ApplicationInsights\\Commands.ApplicationInsights.Test\\bin\\Debug\\Microsoft.Azure.Commands.ApplicationInsights.Test.dll"