Next Generation of the LuaRocks test suite

In this project we focus on package manager for Lua modules, LuaRocks. Our main goal is to increase quality of test suite, because it's implemented as a big shell script that only does black-box testing. So we write new test suite with Lua unit testing framework busted.This will allow us to extend the test suite by writing smarter tests that check its behavior, write white-box tests of the internals, and also port the test suite to other platforms. Next step is to improve code coverage, by adding white-box tests for parts that are hard-to reach via black-box testing. Make tests cross-platform could be a challenge for Windows operating system. At the end we integrated code coverage results, merging the Linux and Windows runs.