Remove tsd task from auto updating typescript definition files

Now that we are using tsd, During a gulp build and even in dev mode builds the typescript definition files are looked up on github and retrieved and placed in 'typings' folder. This takes significant time for our current one file (moment.d.ts) but we should be doing for about 5 other d.ts files. This add build time to Travis builds especially.

This schema information is for development only (typescript compiler hints basically) and it rarely changes – only between version changes of libs.

Because of this, we should manually update this and check the d.ts files into the 'typings' folder (so the build will work).

For tsd reference: https://github.com/DefinitelyTyped/tsd