Build updates. (#462)

Author: jmdobry

cloud-language/snippets/package.json

@@ -19,8 +19,7 @@
   "scripts": {
     "lint": "samples lint",
     "pretest": "npm run lint",
-    "system-test": "ava -T 20s --verbose system-test/*.test.js",
-    "test": "npm run system-test"
+    "test": "samples test run --cmd ava -- -T 20s --verbose system-test/*.test.js"
   },
   "dependencies": {
     "@google-cloud/language": "0.11.0",

cloud-language/snippets/slackbot/package.json

@@ -20,8 +20,7 @@
   "scripts": {
     "lint": "samples lint",
     "pretest": "npm run lint",
-    "system-test": "ava -T 20s --verbose system-test/*.test.js",
-    "test": "npm run system-test"
+    "test": "samples test run --cmd ava -- -T 20s --verbose system-test/*.test.js"
   },
   "dependencies": {
     "@google-cloud/language": "0.11.0",