For #312: Added test coverage limits to project.

[paulodamaso]

For #312: Added test coverage limits to project:

• added jacoco plugin to pom.xml
• configure jacoco to run on jacoco profile
• added coverage limits to the project. As the project now fails when the code coverage is not meet I had to leave some of them below the suggested coverage (0.85)

[coveralls]

Pull Request Test Coverage Report for Build 619

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.05%) to 90.919%

---

Files with Coverage Reduction	New Missed Lines	%
src/main/java/com/amihaiemil/docker/UserAgentRequestHeader.java	1	80.0%
<!--	Total:	1		-->

Totals
Change from base Build 618:	-0.05%
Covered Lines:	871
Relevant Lines:	958

---

💛 - Coveralls

[amihaiemil]

@paulodamaso thanks, looks good!

[0crat]

Job gh:amihaiemil/docker-java-api#327 is not assigned, can't get performer