Add .npmignore, fix #927

.npmignore

@@ -0,0 +1,21 @@
+.DS_Store
+.browse.VC.db
+vscode-chrome-debug.txt
+npm-debug.log
+*.vsix
+gulpfile.js
+tsconfig.json
+tslint.json
+
+lib/
+node_modules/
+typings/
+testapp/.vscode/chrome
+testapp/**/out/
+test-results.xml
+bin
+obj
+logs
+out/test/
+testdata/
+test/