build: add -Wno-error to resource build

Problem: clang-3.8 doesn't grok -Wno-maybe-uninitialized,
and gcc-5.4.0 doesn't grok -Wno-error=unknown-warning-option.

For now, add -Wno-error in the resource directory
and drop -Wno-maybe-uninitialized so we can get this built
on travis.

resource/Makefile.am

@@ -3,7 +3,7 @@ AM_CXXFLAGS = \
     -Wno-unused-local-typedefs \
     -Wno-deprecated-declarations \
     -Wno-unused-variable \
-    -Wno-maybe-uninitialized \
+    -Wno-error \
     $(CODE_COVERAGE_CXXFLAGS)
 
 AM_LDFLAGS = $(CODE_COVERAGE_LDFLAGS) \