Add option to define gollum path from command line. This way we can use different git repo for wiki files and different repo for

gollum.

bin/gollum

@@ -53,6 +53,10 @@ opts = OptionParser.new do |opts|
     wiki_options[:base_path] = path
   end
 
+  opts.on("--gollum-path [PATH]", "Specify the gollum path.") do |path|
+    wiki_options[:gollum_path] = path
+  end
+
   opts.on("--ref [REF]", "Specify the repository ref to use (default: master).") do |ref|
     wiki_options[:ref] = ref
   end
@@ -78,7 +82,11 @@ rescue OptionParser::InvalidOption
   exit
 end
 
-gollum_path = ARGV[0] || Dir.pwd
+if wiki_options[:gollum_path] then
+  gollum_path = wiki_options[:gollum_path]
+else
+  gollum_path = ARGV[0] || Dir.pwd
+end
 
 if options['irb']
   require 'irb'