[Testing:Travis] Simplify and speed-up running the e2e matrix (#5210)
[Testing:Travis] Simplify and speed-up running the e2e matrix (#5210)

* [Testing:Travis] Simplify and speed-up running the e2e matrix

* Update .travis.yml

* print out authentication method before running e2e tests

* Update .travis.yml

* fix echo line

Signed-off-by: Matthew Peveler <ceb7192332cc0210660ce4c985cae5ba0e431884@gmail.com>
Submitty/Submitty,RCOS-Grading-Server/HWserver,Submitty/Submitty,RCOS-Grading-Server/HWserver,RCOS-Grading-Server/HWserver,Submitty/Submitty,RCOS-Grading-Server/HWserver,RCOS-Grading-Server/HWserver,Submitty/Submitty,Submitty/Submitty,RCOS-Grading-Server/HWserver,Submitty/Submitty,RCOS-Grading-Server/HWserver,Submitty/Submitty,Submitty/Submitty,Submitty/Submitty,RCOS-Grading-Server/HWserver,RCOS-Grading-Server/HWserver