Update simplejson version to 3.8.1
Update simplejson version to 3.8.1

wagnerand/amo-validator,wagnerand/amo-validator,mozilla/amo-validator,diox/amo-validator,mozilla/amo-validator,diox/amo-validator,wagnerand/amo-validator,diox/amo-validator,mozilla/amo-validator,diox/amo-validator,wagnerand/amo-validator,mozilla/amo-validator