added missing dependency

Signed-off-by: Nemanja Veskovic <[email protected]>

Author: nveskovic

doc/mac-build.md

@@ -10,6 +10,7 @@
    brew install autoconf
    brew install cmake
    brew install openssl
+   brew install zeromq
    ```
 
 
@@ -34,4 +35,4 @@
 # Note on running local nodes
 
 In order to run local nodes on MacOS, it may be necessary to set up port mapping between the Docker container
-and local host. Follow the instructions in [Indy SDK README](https://github.com/hyperledger/indy-sdk#how-to-start-local-nodes-pool-with-docker)
+and local host. Follow the instructions in [Indy SDK README](https://github.com/hyperledger/indy-sdk#how-to-start-local-nodes-pool-with-docker)