Add Autoscaler e2e tests

[zyjiaobj]

End2end test for autoscaler tab:

• deploy a new application from github url
• go to autoscaler tab, the status should be disabled since no policy is attached
• go to enable it by creating a policy and save
• go to edit policy from instance number setting, trigger table, schedule table of the autoscaler tab
• go to metrics page from autoscaler tab
• go to scaling event page from autoscaler tab
• delete the application

Test log:

  Autoscaler -

    Should deploy app from Git URL
      ✓ Check deploy steps
      ✓ Should pass CF/Org/Space Step
      ✓ Should pass Source step
      ✓ Should pass Source Config step
      ✓ Should pass Overrides step
      ✓ Should Deploy Application
      ✓ Should go to App Summary Page

    Tab Tests -
      ✓ Autoscale Tab -- Disabled

    Autoscaler Attach Policy -
      ✓ Check edit steps
      ✓ Should pass DefaultInstanceLimits Step
      ✓ Should pass ScalingRules Step
      ✓ Should pass RecurringSchedules Step
      ✓ Should pass SpecificDates Step
      ✓ Should go to App Autoscaler Tab

    Autoscaler Edit Policy -
      ✓ Check edit steps
      ✓ Should pass DefaultInstanceLimits Step
      ✓ Should pass ScalingRules Step
      ✓ Should pass RecurringSchedules Step
      ✓ Should pass SpecificDates Step
      ✓ Should go to App Autoscaler Tab

    Autoscaler Metric Page -

      From autoscaler metric card
        ✓ Go to metric page
        ✓ Should go to App Autoscaler Tab

    Autoscaler Event Page -

      From autoscaler event card
        ✓ Go to events page
        ✓ Should go to App Autoscaler Tab

    Autoscaler Detach Policy -
      ✓ Cancel detach action
      ✓ Confirm detach action

[cfdreddbot]

✅ Hey zyjiaobj! The commit authors and yourself have already signed the CLA.

[codecov]

Codecov Report

Merging #3681 into v2-master will decrease coverage by <.01%.
The diff coverage is 70%.

@@              Coverage Diff              @@
##           v2-master    #3681      +/-   ##
=============================================
- Coverage      52.22%   52.21%   -0.01%     
=============================================
  Files            785      785              
  Lines          23010    23015       +5     
  Branches        4124     4125       +1     
=============================================
+ Hits           12017    12018       +1     
- Misses         10993    10997       +4

[richard-cox]

• I've moved common deploy code into a helper function and tested the non-autoscaler part. In the future we might drop this part and use the existing go-env app for autoscaler tests (the deploy step process can be brittle)
• There's a number of e2e.sleep, we've tried to avoid these by using wait functions which should be available on most pages and components
• I still need to come back and test autoscaler features (after polling change) and e2e tests

[richard-cox]

@zyjiaobj I've resolved merge conflicts and updated the PR with a few tweaks.

• Timezone/Format issues
  • This was why the tests failed for me, there's a different format shown in my browser, along with a 24h time shown in date/time controls. I've updated the code to be more agnostic but it still depends on format strings. Is there any way these can be determined at test run time?
  • The form fill of date/time strings used a regex that would also need updating
• The test for scaling events waits for 30 seconds, however in SCF there doesn't seem to be any events after this pause. I need to investigate if these do eventually come up

[richard-cox]

Tested locally against an SCF with autoscaler enabled in eng cloud and everything passes fine. Once we've updated our travis SCF instance with autoscaler I'll bump this through the travis gates and get it merged.

[richard-cox]

Updated with some improvements from another PR, now blocked on #4035