CP-1124 Fix browser file detection (dart2js output changed)

[evanweible-wf]

Issue

• The dart2js analyze output that we use to detect whether or not a dart file imports dart:html changed from "Error: library not found" to "Error: library not supported"
• Also, the project paths for browser/vm test fixtures were swapped

Changes

Source:

• Use a regex to detect either the old error message or the new one so that this detection works on pre-1.13 and 1.13
• Fix the project fixture paths

Tests:

• Current tests already cover this (which is why our CI started failing)

Areas of Regression

• Coverage collection on browser tests without a custom HTML file

Testing

• CI (which is on 1.13 now) passes

Code Review

@trentgrover-wf
@maxwellpeterson-wf
@dustinlessard-wf
@jayudey-wf

[trentgrover-wf]

+1

[codecov-io]

Current coverage is 48.05%

Merging #98 into master will not affect coverage as of 8708cf7

Powered by Codecov. Updated on successful CI builds.

[maxwellpeterson-wf]

+1

[dustinlessard-wf]

+1

[evanweible-wf]

@jayudey-wf ready for merge.

[jayudey-wf]

QA Resource Approval: +10

• Testing instruction
• Dev +1's
• Dev/QA +10 with detail of what was tested
  • verified that travis build completed successfully
• Unit test created/updated
• All unit tests pass

Merging into master.