Updates for base branch rename

Author: ararslan

.github/workflows/ci.yml

@@ -1,7 +1,7 @@
 name: CI
 on:
   push:
-    branches: [master]
+    branches: [main]
     tags: ["*"]
   pull_request:
 jobs:

README.md

@@ -1,7 +1,7 @@
 # FrankenTuples.jl
 
-[![Build status](https://github.com/ararslan/FrankenTuples.jl/workflows/CI/badge.svg)](https://github.com/ararslan/FrankenTuples.jl/actions?query=workflow%3ACI+branch%3Amaster)
-[![codecov](https://codecov.io/gh/ararslan/FrankenTuples.jl/branch/master/graph/badge.svg?token=G47EaAAqKi)](https://codecov.io/gh/ararslan/FrankenTuples.jl)
+[![Build status](https://github.com/ararslan/FrankenTuples.jl/workflows/CI/badge.svg)](https://github.com/ararslan/FrankenTuples.jl/actions?query=workflow%3ACI+branch%3Amain)
+[![codecov](https://codecov.io/gh/ararslan/FrankenTuples.jl/branch/main/graph/badge.svg?token=G47EaAAqKi)](https://codecov.io/gh/ararslan/FrankenTuples.jl)
 [![][docs-latest-img]][docs-latest-url]
 
 This package defines a type, `FrankenTuple`, which is like a cross between a `Tuple` and a