Updating Travis docs script so that it verifies all modules on PRs.

Author: dhermes

scripts/update_docs.sh

@@ -25,7 +25,10 @@ if [[ "${TRAVIS_BRANCH}" == "master" ]] && \
 elif [[ -n "${TRAVIS_TAG}" ]]; then
   echo "Building new docs on a tag."
 else
-  echo "Not on Travis, doing nothing."
+  echo "No docs to build for a new tag or merged commit on Travis."
+  echo "Verifying all modules included (rather than running tox -e docs)."
+  pip install --upgrade Sphinx
+  python scripts/verify_included_modules.py
   exit
 fi