More flexibility in setup

[ryankilf]

I've added a few extra configurable details.

• max length of field.
• Custom issue and issue label separator
• End user can use a - to force basic details.

I totally get if you don't want these but I thought you might want it.

[gsingers]

@ryankilf overall looks good, one minor question inline on the files.

[gsingers]

Also, please update the README at the bottom where it explains the options. Thanks!

[ryankilf]

I'll get those changes made for clarity's sake now.

[gsingers]

@ryankilf what does the bot_id variable do that bot_name doesn't? Seems like a redundant add.