Make compile() return a Result

closes #4
Add Damien Schoof to AUTHORS
Add a .travis.yml file

Following the instructions at: http://hiho.io/rust-ci/help/
Try a different PPA for a newer libpcre
Fix the gimp-standalone PPA package name for libpcre
Force the apt-get install

Trying to fix:
https://travis-ci.org/cadencemarseille/rust-pcre/builds/13779122
Try --force-yes
Another attempt to fix the "trying to overwrite" Travis build error

http://askubuntu.com/questions/176121/dpkg-error-trying-to-overwrite-fil
e-which-is-also-in
Need an apt-get command

https://travis-ci.org/cadencemarseille/rust-pcre/builds/13779685
Need to install libpcre3gsa as well

https://travis-ci.org/cadencemarseille/rust-pcre/builds/13779783
Also install libpcrecpp0gsa
Use PCRE_LIBS to hard-code the libs for libpcre3gsa-dev
Use LD_LIBRARY_PATH
Use asterisks/file globs to be less dependent on the exact .deb filenames
Add a Travis CI build status image