chore: update npm scripts and synth.py (#439)

Update npm scripts: add clean, prelint, prefix; make sure that lint and fix are set properly. Use post-process feature of synthtool.

package.json

@@ -26,14 +26,16 @@
   ],
   "scripts": {
     "docs": "jsdoc -c .jsdoc.js",
-    "lint": "eslint '**/*.js'",
+    "lint": "gts check",
     "samples-test": "cd samples/ && npm link ../ && npm test && cd ../",
     "system-test": "mocha system-test/*.js --timeout 1200000",
     "test": "c8 mocha",
-    "fix": "eslint --fix '**/*.js'",
+    "fix": "gts fix",
     "docs-test": "linkinator docs",
     "predocs-test": "npm run docs",
-    "prelint": "cd samples; npm link ../; npm i"
+    "prelint": "cd samples; npm link ../; npm install",
+    "clean": "gts clean",
+    "precompile": "gts clean"
   },
   "dependencies": {
     "@google-cloud/common": "^3.0.0",

synth.py

@@ -1,5 +1,6 @@
 import synthtool as s
 import synthtool.gcp as gcp
+import synthtool.languages.node as node
 import logging
 
 logging.basicConfig(level=logging.DEBUG)
@@ -9,3 +10,5 @@
 common_templates = gcp.CommonTemplates()
 templates = common_templates.node_library()
 s.copy(templates)
+node.install()
+node.fix()