[LTP] [PATCH 2/2] travis: Enhance docparse testing

[Petr Vorel]

> Hi!
> Looks good.

> Is this making the build significantly slower? If not let's get this in
> now so that we have metadata covered by travis as well.

53 min with [1] vs. 36 min [2] without. That's quite a big difference.
But other build got only 39 min [3], thus running yet another build [4]
to see what's going on. I'd like to have this docparse testing in travis.

Kind regards,
Petr

[1] https://travis-ci.org/github/pevik/ltp/builds/770930869
[2] https://travis-ci.org/github/pevik/ltp/builds/770895636
[3] https://travis-ci.org/github/pevik/ltp/builds/771055881
[4] https://travis-ci.org/github/pevik/ltp/builds/771117708