Style and Build updates

Removing some unneeded dev dependencies and fixing a code-style warning.

Readme graciously updated by @ryross.

No functionality updated.

PHP 7

PHP v7 is now the minimum version. All support for v5 has been removed. Enjoy!

PHP 5 LTS

This is the final version for php v5, with a minimum of v5.6.

Adds support for 5.6 and HHVM

Builds now test against HHVM and will fail if not supported by PHP 5.6.

Convert traits and update documentation

After an initial review, I determined that traits were not necessary. The documentation also needed tweaks and examples added.

Enjoy!

Initial Release

PHP is woefully missing range objects in it's core distribution. The range() function is insufficient. I was inspired by a discussion by Martin Fowler to port his examples to PHP and expand upon them. Looking into DDD, I also decided to include enablements.