Tag implications: messenger_bag -> shoulder_bag -> bag

Current state:

• messenger_bag -> bag
• shoulder_bag -> bag

Proposed state:

• messenger_bag -> shoulder_bag -> bag

Reason:

A messenger bag is a type of shoulder bag.

*bumps*

The code would be:

remove implication shoulder_bag -> bag
create implication messenger_bag -> shoulder_bag

Well we want to keep shoulder_bag -> bag so I just did:
create implication messenger_bag -> shoulder_bag

Guess he meant

remove implication messenger_bag -> bag

Since now messenger_bag implicates both bag and shoulder_bag, and shoulder_bag implicates bag again. Don't know if those double implications make any difference, though.

I don't think it affects anything but I'll remove the extra.