$ cd ~/Desktop/projects/project1
$ brew switch phantomjs 2.0.0
Cleaning /usr/local/Cellar/phantomjs/1.9.7_1
Cleaning /usr/local/Cellar/phantomjs/1.9.8
Cleaning /usr/local/Cellar/phantomjs/2.0.0
2 links created for /usr/local/Cellar/phantomjs/2.0.0

$ cd ~/Desktop/projects/project2
$ brew switch phantomjs 1.9.8
Cleaning /usr/local/Cellar/phantomjs/1.9.7_1
Cleaning /usr/local/Cellar/phantomjs/1.9.8
Cleaning /usr/local/Cellar/phantomjs/2.0.0
2 links created for /usr/local/Cellar/phantomjs/1.9.8