Update .gitignore to ignore node_modules for TypeScript compilation.
Update .gitignore to ignore node_modules for TypeScript compilation.

mikaturunen/mooc-java-serverside-recap,mikaturunen/mooc-java-serverside-recap,mikaturunen/mooc-java-serverside-recap,mikaturunen/mooc-java-serverside-recap,mikaturunen/mooc-java-serverside-recap