Updated deprecation notice

Deprecation notice says to use `notify_object`.  Should be `notified_object`.
update views generator path to account for namespacing
add self to contributors
add views generator instructions to README
Merge pull request #290 from searsaw/patch-1

Updated deprecation notice
Merge pull request #291 from supremebeing7/master

Fix views generator in v0.12.1
Added missing STI and reference indices on mailboxer_conversation_opt_outs, mailboxer_notifications, and mailboxer_receipts.

Please note, that "functional" indices (e.g., read/unread messages, etc.) should be added in the future as well.
Merge pull request #294 from lbeder/master

Added missing STI and reference indices
Bump version to 0.12.2