[ci-pypi] Only build docs if a 'doc' directory exists

ci/pypi.sh

@@ -56,10 +56,12 @@ green_echo "[>>] Uploading first to ${TESTSERVER} on behalf of ${PYPIUSER}..."
 setup check sdist --formats zip upload --repository staging
 green_echo "[<<] Test finished, proceeding..."
 
-# if that worked, uploads documentation to pythonhosted
-green_echo "[>>] Uploading documentation on behalf of ${PYPIUSER}..."
-setup upload_docs --upload-dir sphinx
-green_echo "[<<] Documentation uploaded, proceeding..."
+# if that worked, uploads documentation to pythonhosted if any exists
+if [ -d doc ]; then
+  green_echo "[>>] Uploading documentation on behalf of ${PYPIUSER}..."
+  setup upload_docs --upload-dir sphinx
+  green_echo "[<<] Documentation uploaded, proceeding..."
+fi
 
 # if that worked, uploads source package to the production index
 green_echo "[>>] Uploading package to ${PYPISERVER} on behalf of ${PYPIUSER}..."