Allow doctype declaration for JaCoCo

[gesellix]

After the fix for Cobertura as in #16, I now have the same issue for JaCoCo. See https://travis-ci.org/gesellix-docker/docker-client/builds/29244127 for an example.

This PR extracts the XmlParser and its configuration into a factory to avoid future inconsistencies.

Some unused imports have been removed, too :)

[coveralls]

Coverage increased (+0.01%) when pulling a67c75d on gesellix:allow-DOCTYPE-declaration-jacoco into 874038a on kt3k:master.

[kt3k]

Hi! @gesellix

Thanks for the contribution again!

It seems a nice refactoring. So I'll merge it.

But because I'd like to follow the guideline of Domain Driven Design (of Eric Evans) as far as possible, maybe I'm going to change some file paths a little later.

Thanks,

[gesellix]

I guess following the DDD principle won't be a bad idea, so I don't have a problem with changing paths. Thanks for merging! Just as a side note: I still don't understand where the issue really comes from, on my system the default is as expected, only on travis-ci the XmlParser seems to have another config.

[kt3k]

Thanks for the note. Hmm... maybe something is wrong with xmlparser default settings in travis-ci?

By the way I deployed a version including this fix as v0.6.1.

Thanks!