Change double quotes to single quotes in paths for svn and hg downloader

lib/cocoapods/downloader/mercurial.rb

@@ -12,11 +12,11 @@ module Pod
       end
 
       def download_head
-        hg "clone '#{url}' '#{target_path}'"
+        hg "clone \"#{url}\" \"#{target_path}\""
       end
 
       def download_revision
-        hg "clone '#{url}' --rev '#{options[:revision]}' '#{target_path}'"
+        hg "clone \"#{url}\" --rev '#{options[:revision]}' \"#{target_path}\""
       end
     end
   end

lib/cocoapods/downloader/subversion.rb

@@ -12,11 +12,11 @@ module Pod
       end
 
       def download_head
-        svn "checkout '#{url}' '#{target_path}'"
+        svn "checkout \"#{url}\" \"#{target_path}\""
       end
 
       def download_revision
-        svn "checkout '#{url}' -r '#{options[:revision]}' '#{target_path}'"
+        svn "checkout \"#{url}\" -r '#{options[:revision]}' \"#{target_path}\""
       end
     end
   end