Avoid nesting cloned OGM repos inside themselves

Providing both `directory` and `path` to Git.clone results in
the repo being cloned into a directory nested inside itself.

This may be a fix for #144.

Author: thatbudakguy

lib/geo_combine/harvester.rb

@@ -73,7 +73,7 @@ def clone(repo = nil)
       return 0 if File.directory? repo_path
 
       repo_url = "https://github.com/OpenGeoMetadata/#{repo}.git"
-      Git.clone(repo_url, repo, path: repo_path, depth: 1) && 1
+      Git.clone(repo_url, nil, path: ogm_path, depth: 1) && 1
     end
 
     private