Jest for /libs and /xplat

[dmitryr117]

I am working on making Jest to be used as test suite across the board because NX uses Jest by default and Xplat setup these days is suffering from issues when trying to run tests in NX workspace with Xplat.

Fixes:

1. Configured Jest to run tests for /libs and /xplat

2. Had to change yarn run test files to test for jest config files rather than karma files

3. Commented out original .spec.ts workspace test file contents and added generic tests
   to /xplat and angular web apps to make sure Jest just works for now. Tests inside
   /libs were left untouched and are passing ok.

Issues:

1. Currently after setup "jest-jasmine2" npm package has to be added manually, and
   "jest-preset-angular" npm package has to be set to "^8.0.0" manually inside workspace
   root package.json

2. When local verdaccio hosted @nstudio package dependencies are set to "*" instead of real version inside
   package.json files, which are located inside inside /packages/[package-name] folders - it results
   in error when trying to run "nx generate app". Error is as follows:
   Package "" refers to a non-existing file '"/home/[home-folder]/dev/xplat-tests/angular"'
   If real versions are set inside /packages/[packagename]/package.json files - this error
   does not occur.

closes #170

[NathanWalker]

@dmitryr117 great work here 👏
I saw your comment on the other issue and greatly appreciate this. Having on this PR will help allow me to give it a run. I'll take a look this weekend to see if I can push some additional fixes to help get this wrapped up.

[dmitryr117]

@NathanWalker I also updated the way .travis.yml works. There seems to have been an issue with TravisCI default setup. Basically Yarn was some old version, 1.3.2 I think, and was crashing test builds. I changed the system to instead use a Docker container based on ubuntu:18.04 image with Node 12.x, and latest Yarn. Now everything seems to work, and tests are passing ok.

[NathanWalker]

@dmitryr117 fantastic work! Let's plan to merge this on Wednesday towards end of day PST. I want to run it locally to confirm a few things and will post an update with this. 🤗

[NathanWalker]

I added the root dependency handlers for jest-jasmine2 and jest-preset-angular as well as fixed up some other dependency issues - Will push changes for merge shortly.

[NathanWalker]

This is published now in 9.0.1