bumpversion: optimise script

- no longer require parsing the new version from bumpversion output. We can just push the tags using `git push --tags` and this will push just the new one that's been created
- we do not need to specify `--no-commit` since this is the default behaviour
- remove the 'v' prefix from git tag by using the `--tag-name` parameter

Author: Stefan Hattrell

bumpversion.sh

@@ -4,9 +4,9 @@ set -euxo pipefail
 
 main() {
   git fetch --prune origin "+refs/tags/*:refs/tags/*"
-  NEW_VERSION=$(bump2version --current-version $(git describe) --list --no-commit --tag \
-  --tag-message 'Bump version to {new_version}' patch | grep -oP '^new_version=\K.*$')
-  git push origin tag v$NEW_VERSION
+  bump2version --current-version $(git describe) \
+    --tag --tag-name {new_version} --tag-message 'Bump version to {new_version}' patch
+  git push --tags
 
   exit 0
 }