Ignore unnecessary files at release time

- `client/views/` contains templates whose built version is provided
  with each releases
- `.gitignore` doesn't appear in our releases, but I'm not sure if this
  comes from npm itself or Travis CI publishing for us. Adding it here
  for completeness.
- Surprisingly, `.npmignore` itself is not ignored...
- All other files and directories are for development purposes only

.gitignore

@@ -1,5 +1,3 @@
-# Make sure to keep this file and .npmignore in sync
-
 node_modules/
 npm-debug.log
 

.npmignore

@@ -1,5 +1,19 @@
-# This should match the .gitignore file without the generated assets
+# This file must not contain generated assets listed in .gitignore.
 # npm-debug.log and node_modules/ are ignored by default.
 # See https://docs.npmjs.com/misc/developers#keeping-files-out-of-your-package
 
+client/views/
 coverage/
+scripts/
+test/
+.editorconfig
+.eslintignore
+.eslintrc.yml
+.gitattributes
+.gitignore
+.istanbul.yml
+.npmignore
+.stylelintrc
+.travis.yml
+appveyor.yml
+Gruntfile.js