[test] Add codacy coverage support to to .travis.yaml

[MayeulC]

Yeah, I just did this test commit from the web interface, I'll do it properly later if that's useful.

[coveralls]

Pull Request Test Coverage Report for Build 19

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 40.682%

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Totals
Change from base Build 11:	0.0%
Covered Lines:	334
Relevant Lines:	821

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💛 - Coveralls