Merge pull request #84 from rado-h/upstream-master

Closes #83
New travis-ci config

Hopefully, this fixes the memcache extension installation that causes the build to error.
Set the response headers and data in constructor, accessible through getHeaders and getData methods
Inject the headers and data from response into exception
Default $code to 0
Merge pull request #86 from alexbilbie/useful-exception

Added HTTP response header and data arrays to exception
Merge remote branch 'upstream/master'