Merge pull request #254 from ifad/feature/improve-convert-command

Fix ImageMagick command for v7 option handling

lib/heathen/processor_methods/convert_image.rb

@@ -4,14 +4,14 @@ class Processor
     # utility from ImageMagick. Sets the job content to the new format.
     # @param to [String] the format to convert to (suffix)
     # @param params [Array] optional parameters to pass to the convert program.
-    def convert_image to: 'tiff', params: nil
+    def convert_image to: 'tiff', params: ''
       expect_mime_type 'image/*'
 
       target_file = temp_file_name '', ".#{to.to_s}"
       executioner.execute(
         *[Colore::C_.convert_path,
-        params.split(/ +/),
         job.content_file,
+        params.split(/ +/),
         target_file].flatten
       )
       raise ConversionFailed.new if executioner.last_exit_status != 0