Finish master -> main transition.

.github/workflows/ci.yml

@@ -2,7 +2,7 @@ name: CI
 on:
   pull_request:
   push:
-    branches: master
+    branches: main
 defaults:
   run:
     shell: bash

README.rst

@@ -1,5 +1,5 @@
-.. image:: https://github.com/pex-tool/p537/workflows/CI/badge.svg?branch=master
-    :target: https://github.com/pex-tool/p537/actions?query=branch%3Amaster+workflow%3ACI
+.. image:: https://github.com/pex-tool/p537/workflows/CI/badge.svg?branch=main
+    :target: https://github.com/pex-tool/p537/actions?query=branch%3Amain+workflow%3ACI
 .. image:: https://img.shields.io/pypi/l/p537.svg
     :target: https://pypi.org/project/p537/
 .. image:: https://img.shields.io/pypi/v/p537.svg

RELEASE.md

@@ -5,19 +5,19 @@
 ### Version Bump
 
 Bump the version in [`setup.py`](setup.py) and then open a PR with ths change and land it on
-https://github.com/pex-tool/p537 master.
+https://github.com/pex-tool/p537 main.
 
 ## Release
 
 ### Push Release Tag
 
-Sync a local branch with https://github.com/pex-tool/p537 master and confirm it has the version bump
+Sync a local branch with https://github.com/pex-tool/p537 main and confirm it has the version bump
 and changelog update as the tip commit.
 
-Tag the release as `v<version>` and push the tag to https://github.com/pex-tool/p537 master:
+Tag the release as `v<version>` and push the tag to https://github.com/pex-tool/p537 main:
 ```
 $ git tag --sign -am 'Release 1.0.6' v1.0.6
-$ git push --tags https://github.com/pex-tool/p537 HEAD:master
+$ git push --tags https://github.com/pex-tool/p537 HEAD:main
 ```
 
 The release to PyPI is automated from there. You can check on the release action