text: Title: Hobbies corpus unicode decoding error on Windows x64 (AppVeyor)
  Body: **Describe the bug**
  
  There appears to be a unicode decoding error on Python 3 in Windows when loading the hobbies corpus. This was observed in AppVeyor builds that use the hobbies corpus during testing such as #489 but is probably true for any Windows machine. 
  
  **To Reproduce**
  
  ```python
  from tests.dataset import DatasetMixin
  
  datasets = DatasetMixin() 
  hobbies = datasets.load_data('hobbies')
  ```
  
  **Expected behavior**
  
  We should either remove the unicode encoding from the corpus dataset (unless we beleive that this is a positive feature for the tests ... though currently the encoding of the data does not matter to visualizer performance) or we should fix the datasets to correctly decode the data from disk. 
  
  **Traceback**
  
  ```
  tests\dataset.py:197: in load_data
      return DatasetMixin.load_corpus(name, fixtures)
  tests\dataset.py:230: in load_corpus
      data.append(f.read())
  _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
  self = <encodings.cp1252.IncrementalDecoder object at 0x0000001C91A0D828>
  input = b'The Lonely City\xc2\xa0bristles with heart-piercing wisdom. Loneliness, according to Laing, feels \xe2\x80\x9clike b...an read The\xc2\xa0Rumpus\xe2\x80\x99s review of\xc2\xa0The Lonely City\xc2\xa0right\xc2\xa0here.)\n\nRelated Posts:\n'
  final = True
      def decode(self, input, final=False):
  >       return codecs.charmap_decode(input,self.errors,decoding_table)[0]
  E       UnicodeDecodeError: 'charmap' codec can't decode byte 0x9d in position 164: character maps to <undefined>
  C:\Python36-x64\lib\encodings\cp1252.py:23: UnicodeDecodeError
  ```
  
  **Desktop (please complete the following information):**
   - OS: `AppVeyor Winx64`
   - Python Version `PYTHON=C:\Python36-x64, PYTHON_VERSION=3.6.4, PYTHON_ARCH=64`
   - Yellowbrick Version `develop`
  
  **Additional context**
  
  See [AppVeyor Build 0.7.300](https://ci.appveyor.com/project/districtdatalabs/yellowbrick/build/0.7.300/job/wy9k5x9linoc6tf8) - note that tests _passed_ in `
  Environment: PYTHON=C:\Python27-x64, PYTHON_VERSION=2.7.14, PYTHON_ARCH=64`
  