Fix/add saucelabs eu dc - #5083

Proposed changes

SauceLabs is expanding their services to other regions in the world. Protractor wants to allow user to easily pick between DCs.

Types of changes

This change allows user to define the backend region from sauce via the sauceRegion property, e.g.

    sauceUser: process.env.SAUCE_USERNAME,
    sauceKey: process.env.SAUCE_ACCESS_KEY,
    sauceRegion: 'eu',

Will run the test against https://ondemand.eu-central-1.saucelabs.com:443/wd/hub/.

    sauceUser: process.env.SAUCE_USERNAME,
    sauceKey: process.env.SAUCE_ACCESS_KEY,
    sauceRegion: 'us',

    // the default
    sauceUser: process.env.SAUCE_USERNAME,
    sauceKey: process.env.SAUCE_ACCESS_KEY,

Will run the test against https://ondemand.saucelabs.com:443/wd/hub/

It will also set the correct url for updating the status of the test