Finish 2.5.0-rc.1
Remove numbering from README
Fix #63 Return rate-limiting info only if contained in response
Always return (null) `rate` property, if no rate-limit info received. See #63
Add note about potentially missing rate-limit info in README, see #63
Fix duplicate code
Fix Scrutinizer issues
_callApi: Drop $method_template param
Fix _buildMultipart return value PHPDoc
Extract _validateSslCertificate method
Add forgotten param for _validateSslCertificate
Remove note about planned SimpleXML support
Use < > in header copyright
Add required PHP extensions to composer.json
Update version to 2.5.0-rc.2
Finish 2.5.0-rc.2