Print not-covered files and lines numbers to the standard output

[orestesgaolin]

Is your feature request related to a problem? Please describe.

Sometimes while checking the coverage for 100% the resulting value may be something like 99% or 99.96% which may be obviously a single line missing or some strange quirk like const constructor.

Run VeryGoodOpenSource/[email protected]
  with:
    exclude: **/*.g.dart **/*.gen.dart **/l10n/*.dart **/l10n/**/*.dart **/main/bootstrap.dart
    path: coverage/lcov.info
    min_coverage: 100
  env:
    FLUTTER_ROOT: /opt/hostedtoolcache/flutter/2.4.0-4.2.pre-beta/x64
    PUB_CACHE: /opt/hostedtoolcache/flutter/2.4.0-4.2.pre-beta/x64/.pub-cache
Error: 99.27797833935018 is less than min_coverage 100

Describe the solution you'd like

It would be awesome to print the list of not covered lines as well:

Run VeryGoodOpenSource/[email protected]
  with:
    exclude: **/*.g.dart **/*.gen.dart **/l10n/*.dart **/l10n/**/*.dart **/main/bootstrap.dart
    path: coverage/lcov.info
    min_coverage: 100
  env:
    FLUTTER_ROOT: /opt/hostedtoolcache/flutter/2.4.0-4.2.pre-beta/x64
    PUB_CACHE: /opt/hostedtoolcache/flutter/2.4.0-4.2.pre-beta/x64/.pub-cache
Error: 99.27797833935018 is less than min_coverage 100
Not covered lines:
   lib/main.dart: 10
   lib/my_bloc.dart: 12

Describe alternatives you've considered

• Running the coverage tests on my local machine.
• Seeing the coverage report as in Generate and HTML reports with the coverage report generated/calculated #19

Additional context

[felangel]

Closed by #47 🎉