Travis builds are failing on install of Protractor version that's incompatible with Node 4 & 5

[mleanos]

Currently, the Travis CI builds are failing on Node 4 & 5, due to the latest version of Protractor being installed. Consequently, a version of the webdriver-manager package is installed that is incompatible with Node 4 & 5.

https://github.com/meanjs/mean/blob/master/.travis.yml#L35

We're not using Protractor directly in the project, since we're using gulp-protractor. The latter installs the expected version of Protractor, thus a compatible version of webdriver-manager.

I don't have much experience with Travis CI, and I'm not aware of a way of testing our .travis.yml configuration, short of committing to a PR.

Could we just change the referenced line in the Travis build config, to be npm install gulp-protractor@">=3.0.0 <4.0.0" to match our version of gulp-protractor? Moreover, why do we have to install Protractor at all, before the project's dev dependencies are installed?

@meanjs/contributors @simison @sujeethk @hyperreality

[lirantal]

@mleanos I don't remember the historical reasons for the travis.yml file but you can definitely open a PR with the suggested change and see how the build works.

[codydaig]

What @lirantal said. Go for the changes and hope for the best! I'd be curious to see if we don't need gulp-protractor directly in the travis.yml file. That would be the ideal situation.

[lirantal]

@mleanos this PR for protractor basically sets up the build in travis so that we don't run E2E on unsupported versions like 4 & 5, and only for 6.9 and higher.
Reference: #1752