Use absolute path to load stub rpmbuild

On Travis, Cmake does not run from the same directory as in our local
build environment. We need to ensure that PATH contains absolute paths
so that Cmake can find our stub rpmbuild.

ci/run_build.sh

@@ -9,7 +9,7 @@ set -o nounset
 
 # Set path to prioritize our utils
 export REAL_PATH="${PATH}"
-export PATH="${SOURCE_DIR}/ci/util:${PATH}"
+export PATH="$(readlink -f "${SOURCE_DIR}")/ci/util:${PATH}"
 echo "PATH IS: $PATH"
 
 # Build