Support multiple hooks on the same repository

I'm guessing this is a fairly unique request, but I need the ability to support multiple hooks on the same repo -- the difference is the branch.

You can see the full [Caddyfile here](https://github.com/grindjs/site/blob/master/Caddyfile), but here’s the relevant bits:

```
git github.com/grindjs/docs {
hook /hooks/deploy-docs {$DOCS_SECRET}
hook_type github
branch master
key /apps/.ssh/id_rsa
path ../resources/docs/master
interval -1
}

git github.com/grindjs/docs {
hook /hooks/deploy-docs {$DOCS_SECRET}
hook_type github
branch 0.7
key /apps/.ssh/id_rsa
path ../resources/docs/0.7
interval -1
}

git github.com/grindjs/docs {
hook /hooks/deploy-docs {$DOCS_SECRET}
hook_type github
branch 0.6
key /apps/.ssh/id_rsa
path ../resources/docs/0.6
interval -1
}
```

Basically I have docs for different versions of the framework in branches that can be updated, however when I push to a branch other than master, I get the following:

```
2017/07/19 02:00:45 github webhook ignored. Error: found different branch 0.7
2017/07/19 02:02:13 github webhook ignored. Error: found different branch 0.6
```

I'm guessing the plugin is hitting the first match and then abandoning?