Also install pkg-config
Also install pkg-config

Not sure how I missed this, but apparently we need this, too.

spurti-chopra/travis-cookbooks,ljharb/travis-cookbooks,vinaykaradia/travis-cookbook-cloned,travis-ci/travis-cookbooks,Distelli/travis-cookbooks,gavioto/travis-cookbooks,dracos/travis-cookbooks,dracos/travis-cookbooks,ljharb/travis-cookbooks,ardock/travis-cookbooks,vinaykaradia/travis-cookbook-cloned,gavioto/travis-cookbooks,vinaykaradia/travis-cookbook-cloned,gavioto/travis-cookbooks,travis-ci/travis-cookbooks,spurti-chopra/travis-cookbooks,Zarthus/travis-cookbooks,gavioto/travis-cookbooks,Zarthus/travis-cookbooks,ljharb/travis-cookbooks,ardock/travis-cookbooks,Distelli/travis-cookbooks,Acidburn0zzz/travis-cookbooks,Acidburn0zzz/travis-cookbooks,Zarthus/travis-cookbooks,Acidburn0zzz/travis-cookbooks,Distelli/travis-cookbooks,spurti-chopra/travis-cookbooks,Distelli/travis-cookbooks,ardock/travis-cookbooks,travis-ci/travis-cookbooks,vinaykaradia/travis-cookbook-cloned,Acidburn0zzz/travis-cookbooks,dracos/travis-cookbooks,vinaykaradia/travis-cookbook-cloned,Zarthus/travis-cookbooks,dracos/travis-cookbooks,ardock/travis-cookbooks