Minor formatting change in documentation (#90)

Author: hiranya911

firebase_admin/firestore.py

@@ -15,7 +15,7 @@
 """Cloud Firestore module.
 
 This module contains utilities for accessing the Google Cloud Firestore databases associated with
-Firebase apps. This requires the google-cloud-firestore Python module.
+Firebase apps. This requires the ``google-cloud-firestore`` Python module.
 """
 
 try:

firebase_admin/storage.py

@@ -15,7 +15,7 @@
 """Firebase Cloud Storage module.
 
 This module contains utilities for accessing Google Cloud Storage buckets associated with
-Firebase apps. This requires the google-cloud-storage Python module.
+Firebase apps. This requires the ``google-cloud-storage`` Python module.
 """
 
 # pylint: disable=import-error,no-name-in-module