Alanren/integration test (#3657)

* add an extension for integration tests

* setup ads before running test

* test setup

* test cases

* bash script

* shorter temp folder name

* code cleanup

* add commented out original code

* fix test error

* test result path

* rename results file

* change file path

* report smoke test results

* test stablize

* test stablization and configurable test servers

* fix smoke test error

* connection provider

* simplify the integration test script

* add comment

* fix tslint error

* address PR comments

* add temp log to check whether the environment variable is already set

* remove temp log

* move api definition to testapi typing file

* exclude integration tests extension

* address comments

extensions/integration-tests/tsconfig.json

@@ -0,0 +1,15 @@
+{
+	"compilerOptions": {
+		"module": "commonjs",
+		"target": "ES5",
+		"outDir": "out",
+		"noUnusedLocals": true,
+		"lib": [
+			"es2015"
+		],
+		"sourceMap": true
+	},
+	"include": [
+		"src/**/*"
+	]
+}