Adding test project and some obvious simple tests.
Moved test project to correct directory.
Adding path scanner tests and fixing subtle but related to null paths.
Added test for "no installation found"
Added tests around path scanning.
Fixed bug my refactor introduced in assembly loading.
Merge pull request #2 from davidwhitney/master

Added tests to assembly loading and ISiteInstaller instantiation. Fixed bug introduced previously in ISiteInstaller creation.