Update Zend Framework version to allow 2.1.x

Not only 2.0.* are supported, but 2.x.y with x,y != 0. Also, this
module only requires the Zend HTTP component and as such, the
composer.json reflects this change.
Update composer.json with valid SPDX license identifier
Merge pull request #6 from juriansluiman/hotfix/zendframework-version

Hotfix/zendframework version