Prettier - ESLint

[fboucquez]

Hi Steve,

I've been working on prettier and eslint. Trying to make them to work together.
Current problems:

1. TSLint is deprecated and not activated in Travis.
2. The rules are maintained one by one instead of using more standard rules.
3. Keeping the autoformatter in the IDEs is annoying and time-consuming. It's not guaranteed that the VSCode formatter would work the same than IntelliJ or Eclipse.
4. Not every developer would run the formatter (PRs for example) or have the right one.

In this PR:

1. Removed TS Lint
2. Enable Prettier
3. Enable ESLint to work with TS. The rules are the 'recommended ones' plugin:@typescript-eslint/recommended
4. Prettier integrated with TSLint. If there is a formatting issue (dev didn't execute prettier), eslint test will fail
5. Removed all the tslint ignore comments. I had to add some // eslint-disable-next-line
6. Add scripts to package.json

• npm run prettier it reformats the code using the prettier configuration. The first commit will be big but then we shouldn't have reformatting issues.
• npm run lint it validates the code style with eslint, it doesn't change the code
• npm run lint:fix it fixes the code with eslint if possible
• npm run style:fix runs both prettier and eslint --fix

7. Reenabled Travis eslint changes with cache
8. Add a git hook that test eslint (npm run lint)before allowing to commit. We can be sure the style is fine before committing.

TODOs:

1. I had to warn some of the rules that I think we should fix. Eventually, I would turn them on again. I would create new tasks from them.
2. Do we want Semicolon?, DONE: YES: we have decided to keep them
3. The git commit hook may run npm run style:fix, so it styles the code before testing eslint, better chances of getting the modified code right.
4. Should we use AIRBNB rules or these ones are good enough? In another PR. It seems too restricted and too many changes are required. I would keep the plugin:@typescript-eslint/recommended rules
5. Remove // eslint-disable-next-line
6. Migrate require types of imports like const CryptoJS = require('crypto-js'); to import from format

Fixed #407

[rg911]

Great work

PR looks good! I guess we can merge this one first then work on airbnb rules later on!