Homebrew package is updated to the version 0.11.0.
Hardfork 11 scheduled for 2017-07-17 15:00:00 UTC. All witnesses should update immediately.
To update your installation you need to:
Step 1: Update Homebrew:
brew update
Step 2: Reinstall existing Steem installation:
brew reinstall steem
PS: If you don't have Steem installed, just use the following command:
brew install TigerND/core/steem