Derive the version from git tags

Rather than copying the version and keeping them in sync, this uses git
describe to determine that. It still delivers the version in a VERSION
file by letting git replace the version on export.

Author: ekohl

.gitattributes

@@ -0,0 +1 @@
+VERSION export-subst

Makefile

@@ -1,5 +1,5 @@
 NAME := foremanctl
-VERSION := $(shell cat VERSION)
+VERSION := $(shell git describe)
 REQUIREMENTS_YML := $(firstword $(wildcard src/requirements-lock.yml src/requirements.yml))
 
 dist: $(NAME)-$(VERSION).tar.gz

RELEASE.md

@@ -1,12 +1,10 @@
 # Release
 
-To create a release, bump `VERSION`, create a commit and tag.
+To create a release, create a tag.
 It must follow the x.y.z pattern without any prefix.
 
 ```
 VERSION=x.y.z
-echo $VERSION > VERSION
-git commit -m "Release $VERSION" VERSION
 git tag -s "$VERSION" -m "Release $VERSION"
 git push --follow-tags
 ```

VERSION

@@ -1 +1 @@
-1.0.0
+$Format:%(describe)$