add osx instructions to readme

README.md

@@ -3,7 +3,7 @@ Install it
 
 Install dependencies:
 ```
-  # apt install libzmq3-dev libgtk-3-dev libappindicator3-dev golang
+  # apt install libzmq3-dev libgtk-3-dev libappindicator3-dev golang pkg-build
 ```
 
 Build the systray:
@@ -19,3 +19,19 @@ Run bitmask and the systray:
   $ bitmaskd
   $ ./bitmask-systray
 ```
+
+OSX
+----------
+Using homebrew:
+
+```
+  $ brew install golang zmq pkg-build
+  $ git clone 0xacab.org/leap/bitmask-systray
+  $ cd bitmask-systray
+  $ go get .
+  $ go build
+```
+
+Run it
+-------------
+bitmask-systray assumes that you already have bitmaskd running.