v0.1.7

Changes in this release:

• utf-8 encoding specified while reading the Emoji data CSV in order to avoid errors on systems with default formatting other than UTF-8.
• Support to detect multiple emojis in input text and return the sentiment rankings for the detected emojis with their positions in the input text.
• Added unit tests for all functionality using Python builtin unittest module.
• Minor tweaks and reformatting in code and comments.