[BUG] Coverage report not sent to Coveralls

[madmath03]

Description of the issue

Coverage report is not being sent to Coveralls.io during Travis-CI builds.

Same issue than frappe/frappe#9169. Since I already a fix for Frappe, I will send PR for ERPNext too, but I'm also expecting to encounter the same issue as in frappe/frappe#9304...

Context information (for bug reports)

The Root Cause is z4r/python-coveralls#73 : python-coveralls is not compatible with coverage 5.0, thus breaking the report to Coveralls.

Output of bench version
All versions impacted.

Steps to reproduce the issue

1. Travis-CI build

Observed result

Coverage not sent to Coveralls.

Expected result

Coverage not sent to Coveralls.

Stacktrace / full error message

From travis.yml, coveralls -b apps/frappe -d ../../sites/.coverage:

Traceback (most recent call last):
  File "/home/travis/virtualenv/python2.7.14/bin/coveralls", line 11, in <module>
    sys.exit(wear())
  File "/home/travis/virtualenv/python2.7.14/lib/python2.7/site-packages/coveralls/__init__.py", line 78, in wear
    from coveralls.control import coveralls
  File "/home/travis/virtualenv/python2.7.14/lib/python2.7/site-packages/coveralls/control.py", line 2, in <module>
    from coveralls.report import CoverallsReporter
  File "/home/travis/virtualenv/python2.7.14/lib/python2.7/site-packages/coveralls/report.py", line 6, in <module>
    from coverage.report import Reporter
ImportError: cannot import name Reporter

Additional information

N/A