Update writing e2e tests doc
Update writing e2e tests doc

This is a second iteration to address the Resources section.

In a third iteration the Page Object section will be addressed.

mmkassem/gitlabhq,stoplightio/gitlabhq,stoplightio/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq