Make AbstractArraySubject compatible with SubjectFactory

[benjamin-bader]

In the current release of truth, the following is a compile-time error:

new SubjectFactory<PrimitiveByteArraySubject, byte[]> {
  @Override public PrimitiveByteArraySubject getSubject(FailureStrategy fs, byte[] that) {
    return new PrimitiveByteArraySubject(fs, that);
  }
}

This is unfortunate because (until said subject is released) I'd like to assert_().about(byteArray()), but cannot.

This is because AbstractArraySubject<S extends AbstractArraySubject<S, T>, T> extends Subject<AbstractArraySubject<S, T>, T> and not Subject<S, T>; this is incompatible with the generic bounds of S in SubjectFactory. Changing the supertype to Subject<S, T> solves the problem, and doesn't appear to have any adverse effect.

I have implemented this (trivial) fix and signed a CLA, but before opening a pull request I'm wondering:
a) if the current "behavior" is intended, and
b) whether you the maintainers believe this is worth fixing (I do!).

[kluever]

Hmm, I'm not sure I see the problem, but sure, go ahead and send a patch! Thanks :)

[benjamin-bader]

Looks like this was fixed with #149 - thanks much!