Fail fast if asset proxy is disabled
Make asset whitelist configurable
Include original canonical image src after rewriting
Travis no longer builds ruby 1.8
Use more compatible URI#host
Merge branch 'master' into travis
Merge pull request #99 from jch/travis

Remove 1.8 from Travis build
bump version to 1.3.0
Merge remote-tracking branch 'upstream/master' into configurable-schemes-bug-fix
Safely dup protocols by providing default hash