Makes the install command in README file be <code>
Merge pull request #6 from potherca/minor-improvement-to-readme

Makes the install command in README file be <code>
added contributing.md file
Convert simpletest to phpunit
Merge pull request #8 from mjrider/phpunit-conversion

Convert simpletest to phpunit
Adds PHPUnit config file

 - Adds phpunit.xml.dist
 - Removes path to test directory entry from the Travis config file as this is now routed through the PHPUnit config