updated Travis [skip ci]

Author: dmalan

.travis.yml

@@ -20,11 +20,11 @@ deploy:
       \"target_commitish\": \"$TRAVIS_COMMIT\", \"name\": \"v$(python setup.py --version)\"
     }" --user bot50:$GITHUB_TOKEN https://api.github.com/repos/$TRAVIS_REPO_SLUG/releases'
     on:
-      branch: master
+      branch: main
   - provider: pypi
     user: "$PYPI_USERNAME"
     password: "$PYPI_PASSWORD"
-    on: master
+    on: main
 notifications:
   slack:
     secure: 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