Banhammer-py

**Changelog:**
- `Banhammer.get_subreddits_embed()` and `Banhammer.get_reactions_embed()` to show configured subreddits/reactions.
- Cleaned imports.

**Changelog:**
- Add parameters `bot` and `change_presence` in `__init__()` of `Banhammer`.
-> If both are set, Banhammer automatically adjusts the bot's presence to "Playing on /r/subname" when a scan is being done.

**Changelog:**
- Fixed return value of `__str__()` in `Reaction`.
- Using `eligible()` in `handle()` instead of re-creating the check.

**Changelog:**
- `Reaction` overrides `__str__()` to output information about its attributes.
- Improved readability of code.

**Changelog:**
- `Reaction` returns `RedditItem.type` instead of `Reaction.type`.

**Changelog:**
- `RedditItem`'s `get_embed()` method takes `embed_color` as an optional parameter allowing you to customize the color for individual items if that's of interest.
- `Reaction`'s `handle()` method returns a dictionary containing `actions` (`list: str`) in addition to to the other information containing all the actions that were performed such as `removed`, `locked` etc.