[#24]: update deploy to only run on master (#25)

Closes #24

Author: jmag722

.github/workflows/CI.yml

@@ -34,6 +34,7 @@ jobs:
           name: doc-latest
           path: doc/
   deploy:
+    if: github.ref == 'ref/heads/master'
     needs: build-test
 
     # Grant GITHUB_TOKEN the permissions required to make a Pages deployment