Compile TS of the whole project to detect type errors

- was not covered by TS lint
- TS errors are only noticed in broken builds
- added grunt task to run `tsc --noEmit`

scripts/grunt/options/exec.js

@@ -1,8 +1,9 @@
-module.exports = function(config, grunt) {
+module.exports = function (config, grunt) {
   'use strict';
 
   return {
     tslint: 'node ./node_modules/tslint/lib/tslintCli.js -c tslint.json --project ./tsconfig.json',
+    tsc: 'yarn tsc --noEmit',
     jest: 'node ./node_modules/jest-cli/bin/jest.js --maxWorkers 2',
     webpack: 'node ./node_modules/webpack/bin/webpack.js --config scripts/webpack/webpack.prod.js',
   };