feat: automatically generate changelog after version bump

Fixes #23

src/common.ts

@@ -682,6 +682,8 @@ export function getRules(configuration: Configuration): Rules {
     /* tslint:disable-next-line:max-line-length */
     changelog: 'conventional-changelog -p angular -i CHANGELOG.md -s -r 0 && git add CHANGELOG.md && git commit -m \'docs: update changelog\'',
     'check-configuration': 'openstapps-configuration',
+    postversion: 'npm run changelog && git push && git push origin "v$npm_package_version"',
+    preversion: 'npm run prepublishOnly',
     tslint: 'tslint -p tsconfig.json -c tslint.json \'src/**/*.ts\'',
   };