##### ISSUE TYPE
<!--- Pick one below and delete the rest: -->
- Feature Pull Request
Fix for issue [githib-actions](https://github.com/infracloudio/botkube/issues/179)
##### SUMMARY
- Updated the golint path to $GOPATH/bin/golint to fix github-actions build failure.
- Added docker push action step in current CI steps.
- Added helm release step along with missing "helm init".
Checklist for Enabling github actions:
make sure to add below secrets in repo/settings/secrets
- GH_TOKEN(github access token of **charts** repo)
- DOCKER_USERNAME and DOCKER_PASSWORD (for **infracloud/botkube** repo).
- That's it, by merging this PR, first github-actions workflow for botkube should be triggered :)
For reference the tested CI workflows on my repos:
- [with helm release](https://github.com/ameydev/botkube/runs/434885674?check_suite_focus=true)
- [Normal workflow with docker push and helm release skipped](https://github.com/ameydev/botkube/runs/434903893?check_suite_focus=true)
