refactor: drop repo-tool as an exec wrapper (#62)

Author: JustinBeckwith

cloud-language/snippets/package.json

@@ -16,7 +16,7 @@
   "scripts": {
     "ava": "ava -T 20s --verbose test/*.test.js ./system-test/*.test.js",
     "cover": "nyc --reporter=lcov --cache ava -T 20s --verbose test/*.test.js ./system-test/*.test.js && nyc report",
-    "test": "repo-tools test run --cmd npm -- run cover"
+    "test": "npm run cover"
   },
   "dependencies": {
     "@google-cloud/language": "1.2.0",