Write better acceptance tests for new functionality

[vinzent]

Write acceptance tests for #183 , #177, #175, #174

[oranenj]

the existing acceptance tests do test a part of the new providers' functionality. In the fcontext case, I extended the test to even check if purging works.

As of this writing, the fcontext and port providers pass acceptance on centos 6 and 7 at least. Presumably Fedora works too.

[oranenj]

I'm testing with a branch where all three providers have been merged together. Currently successful with CentOS 7.3, and I think I've fixed the remaining issues with CentOS6 as well.

Have to see what happens with Fedora...

[oranenj]

So acceptance tests exist, but they might not be complete as complete as they should be, so I'm still keeping this open