Reduce the number of 3rd party GitHub integrations

[Ingvord]

Currently we have 3 major 3rd party integrations for code quality analyzing:

• Codacy
• Codebeat
• Sonar

And one for code coverage:

• Codecov (jacoco VS cobertura)

We need to choose the one combination (analysis + coverage) that best suits our needs and stay with it.

Here is rough estimation:

Codacy:
PRO
- Nice interface
- Ability to set goals
- Integration with coverage (jacoco or cobertura)
- Ability to exclude certain codebase from analysis
CONTRA
- Missing patterns (e.g. complexity, security etc)
- Wide configuration (may require too much time to setup)

Codebeat
PRO
- Simple intuitive interface
- Reliable analysis patterns with explanations (there is no stupid suggestions on missing javadoc etc)
- Focus on complexity
- Quick wins suggestions
CONTRA
- No integration with coverage

Sonar:
PRO
- was used by Soleil
- Nice issues explorer interface with a lot filters
CONTRA
- requires jacoco (IMHO cobertura produces better report)
- no GitHub badge

[Ingvord]

I have finally managed to get badges for sonar:

In fact it is even more interesting, as we can put as many metrics as we want, see, for instance, this link

So we shall stick with SonarCloud!