chore: update npm scripts and synth.py (#475)

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

Author: alexander-fenster

package.json

@@ -30,7 +30,8 @@
     "license-check": "jsgl --local .",
     "docs-test": "linkinator docs",
     "predocs-test": "npm run docs",
-    "prelint": "cd samples; npm link ../; npm i"
+    "prelint": "cd samples; npm link ../; npm install",
+    "precompile": "gts clean"
   },
   "dependencies": {
     "@google-cloud/common": "^3.0.0",

synth.py

@@ -14,6 +14,7 @@
 
 import synthtool as s
 import synthtool.gcp as gcp
+import synthtool.languages.node as node
 import logging
 
 logging.basicConfig(level=logging.DEBUG)
@@ -23,3 +24,5 @@
 common_templates = gcp.CommonTemplates()
 templates = common_templates.node_library()
 s.copy(templates)
+node.install()
+node.fix()