Simplify test. Check for content, rather than url
Simplify test. Check for content, rather than url

* The test functions were very similar, so this commit refactors out the
  common test code to a single method, and passes in the data to the
  test using the parameterized package.

* Check that the page content after a login attempt is the expected
  content, rather than checking the url.

DannyArends/genenetwork2,genenetwork/genenetwork2,pjotrp/genenetwork2,genenetwork/genenetwork2,DannyArends/genenetwork2,pjotrp/genenetwork2,pjotrp/genenetwork2,DannyArends/genenetwork2,DannyArends/genenetwork2,DannyArends/genenetwork2,pjotrp/genenetwork2,genenetwork/genenetwork2,zsloan/genenetwork2,genenetwork/genenetwork2,DannyArends/genenetwork2,pjotrp/genenetwork2,zsloan/genenetwork2,zsloan/genenetwork2,zsloan/genenetwork2