Ignore pull failures

If we are on a tag we don't need to pull.
@adamstegman You're right, it should only pull if there's an upstream set.

A better way would be:

```bash
git rev-parse @{u} > /dev/null 2>&1 && git pull
```

This way, the pull will only be attempted when there is an upstream, and if the pull fails we'll know.

Also, the PR needs to be submitted against the develop branch.

Thanks
@krishicks && @dliebreich 
CF Community Pair