t pod-spelling.t: Whitelist jN (reference to "-jN" parameter)

Signed-off-by: Niels Thykier <niels@thykier.net>
t: Add dpkg-dev dependency on one of the tests

Signed-off-by: Niels Thykier <niels@thykier.net>
pod-spelling.t: Require aspell-en 7.1-0~

The spelling test fails on Ubuntu Precise.  The spell checker there
does not seem to recognise "indices" or "extendable".  AFAICT the only
difference is that aspell-en is older there.

Note that the choice 7.1-0~ was a guess rather than a precise choice.

Signed-off-by: Niels Thykier <niels@thykier.net>
t/runtests: Fix potential error-hiding bug

Signed-off-by: Niels Thykier <niels@thykier.net>
Add .travis.yml

Installing build deps via mk-build-deps, which may result into more packages
installed than needed (installs with recommends). But this gives us the
freedom of just maintaining the build deps in debian/control.

Signed-off-by: Niels Thykier <niels@thykier.net>
.travis.yml: Only run lintian if the build succeeds

Also, run the current lintian on itself instead of installing the
Ubuntu from the repositories.

Signed-off-by: Niels Thykier <niels@thykier.net>