Ensure signature comparison always takes the same amount of time to avoid Remote Timing Attacks.
Update .travis.yml
Don't convert CURLFile params to JSON

PHP 5.5 will throw deprecation warnings if users are uploading files with the previously documented `'source' => '@/foo/bar.jpg',` syntax.

The new approach is to use `'source' => new CurlFile('/foo/bar.jpg', 'image/jpeg'),`, which obviously avoids accidental uploads (or upload attempts) from user-provided content which starts with a `"@"` character.
and -> &&
Merge pull request #110 from philsturgeon/php55

Dont convert CURLFile: Take 2
Add space to if statement.
Merge pull request #64 from h0ke/master

Fix Remote Timing Attack vulnerability