Tumblr script should not fail on emoji

[wholewheattoast]

Created:  2015-10-19-something-on-my-mind-a-lot-recently-regarding.html
Created:  2015-10-19-witts-last-stand-by-rowlandson-calls-to-mind.html
Traceback (most recent call last):
  File "tumblr_api_tests.py", line 130, in <module>
    "tumblr_photo_post"
  File "tumblr_api_tests.py", line 27, in write_out_template
    html_file.write(html_results)
UnicodeEncodeError: 'ascii' codec can't encode characters in position 335-337: ordinal not in range(128)