Rename test/cl-ppcre.asd to test/test-bad-system-name.asd
Due to the changes !116 (merged), locate-system
incorrectly locates the ~/common-lisp/asdf/test/cl-ppcre.asd
instead of the official .asd file distributed via quicklisp in my (or maybe some) environment(s).
(Travis CI informed me this problem as my test requires cl-ppcre and the HEAD of ASDF.)