Update CI for branch name changes (#480)

and some documentation too!

.github/workflows/ruby.yml

@@ -2,9 +2,9 @@ name: CI
 
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
   pull_request:
-    branches: [ master ]
+    branches: [ main ]
 
 jobs:
   test:

Dangerfile

@@ -18,7 +18,7 @@ declared_trivial = (github.pr_title + github.pr_body).include?('#trivial') || !h
 
 if !git.modified_files.include?('CHANGELOG.md') && !declared_trivial
   error_message = "Please include a CHANGELOG entry. \nYou can find it at " \
-                  '[CHANGELOG.md](https://github.com/ualbertalib/pushmi_pullyu/blob/master/CHANGELOG.md).'
+                  '[CHANGELOG.md](https://github.com/ualbertalib/pushmi_pullyu/blob/main/CHANGELOG.md).'
   fail(error_message, sticky: false)
 end
 

README.md

@@ -86,7 +86,7 @@ You can also provide a configuration file which PushmiPullyu will use with the -
 
 By default, if no configuration file is specified, PushmiPullyu will look for a configuration file at config/pushmi_pullyu.yml.
 
-Take the following [sample configuration](https://github.com/ualbertalib/pushmi_pullyu/blob/master/examples/pushmi_pullyu.yml) as inspiration or check out the [DEFAULTS hash](https://github.com/ualbertalib/pushmi_pullyu/blob/master/lib/pushmi_pullyu.rb) in the main module to see all available options.
+Take the following [sample configuration](https://github.com/ualbertalib/pushmi_pullyu/blob/main/examples/pushmi_pullyu.yml) as inspiration or check out the [DEFAULTS hash](https://github.com/ualbertalib/pushmi_pullyu/blob/main/lib/pushmi_pullyu.rb) in the main module to see all available options.
 
 Options passed on the command line will also override options specified in the config file.
 
@@ -144,7 +144,7 @@ To release a new version, bump the version file found here: `lib/pushmi_pullyu/v
 
 Try to bump versions using [semantic versioning](http://semver.org/).
 
-Commit this change into master branch via a PR.
+Commit this change into main branch via a PR.
 
 Once committed, you can do a release by running the following rake command: