Restore -Werror

Ubuntu 12.04 LTS's flex (2.5.35) generates a redundant declaration.

.travis.yml

@@ -56,4 +56,7 @@ install:
   - export LDFLAGS="$LDFLAGS -L$DESTDIR/usr/lib"
   - sudo ln -sf "$DESTDIR/usr/lib/libsepol.a" /usr/lib/libsepol.a
 
+  # Ubuntu 12.04's flex generates a redundant decl
+  - sed -i -e "/Wwrite-strings/s/,/, '-Wno-redundant-decls',/" setup.py
+
 script: python setup.py test

setup.py

@@ -91,7 +91,7 @@ ext_py_mods = [Extension('setools.policyrep._qpol',
                           'libqpol/policy_scan.c'],
                          include_dirs=['libqpol', 'libqpol/include'],
                          libraries=['bz2', 'selinux', 'sepol'],
-                         extra_compile_args=['-Wextra',
+                         extra_compile_args=['-Werror', '-Wextra',
                                              '-Waggregate-return',
                                              '-Wcast-align',
                                              '-Wfloat-equal',