fix `githubrepo` hook for groups repositories remotes

when there was a repository per group we could not use the hook
for pushing since we only had **one** remote configured. This PR
configures each repository its own remote based in the `groups`
config, as follows:

```
---
groups:
  first:
    remote_repo: git@gitlab.lab:oxidized/first.git
  second:
    remote_repo: git@gitlab.lab:oxidized/second.git
```

1 files changed, 14 insertions, 2 deletions

diff --git a/lib/oxidized/hook/githubrepo.rb b/lib/oxidized/hook/githubrepo.rb
index d10b51e..80ae665 100644
--- a/lib/oxidized/hook/githubrepo.rb
+++ b/lib/oxidized/hook/githubrepo.rb
@@ -4,9 +4,9 @@ class GithubRepo < Oxidized::Hook
   end
 
   def run_hook(ctx)
-    repo = Rugged::Repository.new(Oxidized.config.output.git.repo)
+    repo = Rugged::Repository.new(ctx.node.repo)
     log "Pushing local repository(#{repo.path})..."
-    remote = repo.remotes['origin'] || repo.remotes.create('origin', cfg.remote_repo)
+    remote = repo.remotes['origin'] || repo.remotes.create('origin', remote_repo(ctx.node))
     log "to remote: #{remote.url}"
 
     fetch_and_merge_remote(repo)
@@ -54,4 +54,16 @@ class GithubRepo < Oxidized::Hook
     end
   end
 
+  def remote_repo(node)
+    if node.group.nil? || single_repo?
+      cfg.remote_repo
+    else
+      Oxidized.config.groups[node.group].remote_repo
+    end
+  end
+
+  def single_repo?
+    Oxidized.config.git.single_repo?
+  end
+
 end