enable libtab on travis builds

to enable some more tests

Signed-off-by: Sven Nierlein <Sven.Nierlein@consol.de>

.travis.yml

@@ -15,7 +15,7 @@ install:
 
 before_script:
   - tools/setup
-  - ./configure
+  - ./configure --enable-libtap
   - make
   - export NPTEST_CACHE="$(pwd)/plugins/t/NPTest.cache.travis"
   - ssh-keygen -t dsa -N "" -f ~/.ssh/id_dsa