Fix typo

build-tools/build-for-macos.sh

@@ -1,9 +1,9 @@
 #!/bin/sh
 
 brew install python@2
-pip install --upgrade virtualenv 
+pip install --upgrade virtualenv
 
-# clonde labelimg source
+# clone labelimg source
 rm -rf /tmp/labelImgSetup
 mkdir /tmp/labelImgSetup
 cd /tmp/labelImgSetup
@@ -27,4 +27,4 @@ mv "/tmp/labelImgSetup/labelImg-master/dist/labelImg.app" /Applications
 deactivate
 cd ../
 rm -rf /tmp/labelImgSetup
-echo 'DONE'
+echo 'DONE'