finished object oriented approach
    #done
    - fix when no dir specified
    - incorrect filenames to be fixed
    --- implement oop approach
    #to-do
    - custom filename (wip)
    - search for // #todo: for optimization
    - set mismatch tolerance to 0
    - fix diff image rendering (temp fix involves commenting code in the phantomcss plugin)
    - add livereload to the link (may not be feasible)
    - segregate screefly into its own repo