Rename master branch to release (#985)

It's not our main branch anyway, and "release" makes it more clear what
it's for. There's an industry-wide trend to move away from terms that
invoke master/slave relationships in order to make members of
marginalized populations slightly less uncomfortable.

.build/generate_changelog.sh

@@ -2,7 +2,7 @@
 
 BRANCH=$TRAVIS_BRANCH
 if [[ $TRAVIS_BRANCH == $TRAVIS_TAG ]]; then
-  BRANCH='master'
+  BRANCH='release'
 fi
 
 # Check if branch has been updated since this build started
@@ -39,7 +39,7 @@ elif [[ ! -z $TRAVIS_TAG ]]; then
   echo "beta elease"
   gittag=${release_latest}
 else
-  echo "merge into master or develop"
+  echo "merge into release or develop"
   gittag=${release_latest}
 fi
 echo "gittag: ${gittag}"

CONTRIBUTING.md

@@ -73,7 +73,7 @@ You will need to install [poetry](https://poetry.eustace.io/) to develop jrnl. I
 jrnl uses two primary branches:
 
  * `develop` - for ongoing development
- * `master` - for releases
+ * `release` - for releases
 
 In general, pull requests should be made on the `develop` branch.
 

README.md

@@ -1,4 +1,4 @@
-jrnl [![Build Status](https://travis-ci.com/jrnl-org/jrnl.svg?branch=master)](https://travis-ci.com/jrnl-org/jrnl) [![Downloads](https://pepy.tech/badge/jrnl)](https://pepy.tech/project/jrnl) [![Version](http://img.shields.io/pypi/v/jrnl.svg?style=flat)](https://pypi.python.org/pypi/jrnl/)
+jrnl [![Build Status](https://travis-ci.com/jrnl-org/jrnl.svg?branch=release)](https://travis-ci.com/jrnl-org/jrnl) [![Downloads](https://pepy.tech/badge/jrnl)](https://pepy.tech/project/jrnl) [![Version](http://img.shields.io/pypi/v/jrnl.svg?style=flat)](https://pypi.python.org/pypi/jrnl/)
 ====
 
 _To get help, [submit an issue](https://github.com/jrnl-org/jrnl/issues/new) on