Fix always deploy to default branch problem

[ldarren]

this PR fixes Unitech/pm2#3803 this PR doesn't break any existing api

what this PR does:

• fixed if test fetch != "fast"; always return true problem
• always clone to the specified branch regardless fetch type
• use checkout instead of hard reset for deployment
• allow ref options to have a optional branch name

ref example following command deploy tag prod-v1.0.1 to new branch named v1.0.1

pm2 deploy production ref tags/prod-v1.0.1 v1.0.1

if the optional branch name omitted, the tag will be deploy to branch named prod-v1.0.1

the ref command can also use for branch deployment

pm2 deploy production ref develop

[Unitech]

Cool contribution thank you, merged!

[Unitech]

If I run only

$ pm2 deploy production

This does not work anymore, I'm getting:

unitech@zion:~/edve/de-project$ pm2 deploy production
--> Deploying to production environment
--> on host xxd.com
  ○ deploying origin/master
  ○ executing pre-deploy-local
  ○ hook pre-deploy
  ○ fetching updates
  ○ full fetch
Fetching origin
  ○ checkout origin/master to master
fatal: A branch named 'master' already exists.

  git checkout failed

Deploy failed
1

[Unitech]

I've unmerged the PR as long as it's blocking our deployments systems.

If you could make sure that:

pm2 deploy production setup
pm2 deploy production

Work as expected, we will be able to merge it back. Feel free to re-open a PR as that one can't be opened back. Thank you!

[Unitech]

works perfectly. sorry for the late answer, merged