tvrank-0.7.8

• This release fixes an issue with the mark sub-command writing in correct tvrank.json
  files. The incorrect tvrank.json files looked like this:

  {
    "imdb": {
      "id": {
        "title_id": "ttXXXXX"
      }
    }
  }

  While the correct tvrank.json files should like this:

  {
    "imdb": {
      "id": "ttXXXXXX"
    }
  }

• This release also fixes an issue (#54) with IMDB IDs that end with non-numeric
  characters being accepted. Example: ttXXXXXabc where XXXX are digits.