Changed name of darwin executable to be more clear what it is

Knetic · Knetic · commit 1081d72b4f53 · 2015-07-26T00:07:25.000-07:00
diff --git a/build.sh b/build.sh
@@ -71,7 +71,7 @@ go build -o ./.output/wisk32 .
 
 export GOOS=darwin
 export GOARCH=amd64
-go build -o ./.output/wisk.bin .
+go build -o ./.output/wisk_osx .
 
 export GOOS=windows
 export GOARCH=amd64
