Replace remaining stray references with main (#1582)

Ensure default branch has been fully updated everywhere to main, which
should fix the running of the unit and integration tests on the main
branch.

.github/workflows/docker-image.yml

@@ -3,7 +3,7 @@ name: docker-image
 on:
   push:
     branches:
-      - master
+      - main
     tags:
       - '*.*.*'
   pull_request:

.github/workflows/integration-tests.yml

@@ -3,7 +3,7 @@ name: Integration Tests
 on:
   push:
     branches:
-      - master
+      - main
   pull_request:
 
 jobs:

.github/workflows/unit-tests.yml

@@ -10,7 +10,7 @@ name: CI
 on:
   push:
     branches:
-      - master
+      - main
   pull_request:
 
 jobs:

README.md

@@ -4,7 +4,7 @@
 
 [![Join the chat at https://gitter.im/vagrant-libvirt/vagrant-libvirt](https://badges.gitter.im/vagrant-libvirt/vagrant-libvirt.svg)](https://gitter.im/vagrant-libvirt/vagrant-libvirt?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![Build Status](https://github.com/vagrant-libvirt/vagrant-libvirt/actions/workflows/unit-tests.yml/badge.svg)](https://github.com/vagrant-libvirt/vagrant-libvirt/actions/workflows/unit-tests.yml)
-[![Coverage Status](https://coveralls.io/repos/github/vagrant-libvirt/vagrant-libvirt/badge.svg?branch=master)](https://coveralls.io/github/vagrant-libvirt/vagrant-libvirt?branch=master)
+[![Coverage Status](https://coveralls.io/repos/github/vagrant-libvirt/vagrant-libvirt/badge.svg?branch=main)](https://coveralls.io/github/vagrant-libvirt/vagrant-libvirt?branch=main)
 [![Gem Version](https://badge.fury.io/rb/vagrant-libvirt.svg)](https://badge.fury.io/rb/vagrant-libvirt)
 
 This is a [Vagrant](http://www.vagrantup.com) plugin that adds a

lib/vagrant-libvirt/util/network_util.rb

@@ -120,7 +120,7 @@ module VagrantPlugins
             logger.debug "In config found network type #{type} options #{original_options}"
             # Options can be specified in Vagrantfile in short format (:ip => ...),
             # or provider format # (:libvirt__network_name => ...).
-            # https://github.com/mitchellh/vagrant/blob/master/lib/vagrant/util/scoped_hash_override.rb
+            # https://github.com/mitchellh/vagrant/blob/main/lib/vagrant/util/scoped_hash_override.rb
             options = scoped_hash_override(original_options, :libvirt)
             # store type in options
             # use default values if not already set

tools/prepare_redhat_for_box.sh

@@ -8,7 +8,7 @@
 # After script has finished, nothing else than halting machine should be done.
 
 # For more info about creating custom box refer to
-# https://github.com/vagrant-libvirt/vagrant-libvirt/tree/master/example_box
+# https://github.com/vagrant-libvirt/vagrant-libvirt/tree/main/example_box
 
 # We need to set a hostname.
 if [ $# -ne 1 ]; then