Fix not starting CI and e2e tests

[Dumluregn]

What I did here was basically:

1. Bump Protractor dependency;
2. Then some install scripts in travis.yml became unnecessary so I deleted them;
3. This was not enough as Travis still kept wrong cache, so I cleared it and disabled caching in the future (if we observe dramatic loss of Travis performance we can restore this setting, but for now it turned to be more problematic than beneficial).
4. After all I also updated two invalid Travis config options.

Now CI should work (but it doesn't mean it will be green...). Also thanks to webdriver-manager included in Protractor update, e2e tests should start working (also here it doesn't mean they will pass right away).

Closes #86.
Closes #60.

[f1ames]

Rebased onto latest master.

[f1ames]

Now CI should work (but it doesn't mean it will be green...).

Halfway there then 👍 Good job 🆗