Remove .md only commit check in travis config (#12069)

Author: earnjam

.travis.yml

@@ -19,11 +19,6 @@ cache:
     - $HOME/.npm
 
 before_install:
-  - |
-    git diff --name-only $TRAVIS_COMMIT_RANGE | grep -qvE '(\.md$)' || {
-      echo "Only docs were updated, stopping build process."
-      exit
-    }
   - nvm install && nvm use
   - npm install npm -g