Updated composer version constraints

Updated version constraints and some small tweaks for build.

Updated dependencies and documentation.

Improved stability, code quality and documentation. Updated dependencies.

Small fix

Release fixes a small bug when using CachingMiddleware as library in some other project loaded via composer.

1st stable release to the public

This release marks the first stable release to the public. Well documented and high quality code base, covered by unit-tests between 90 ~ 100%.