+openTill.Testing Project +[ClassBeingTest]Test.cs

Added the testing project and template test file that contains examples
of some harder to do tests
+README.md for openTill.Testing

This also adds the project to the sln as this was missed in the original
commit
*README.md

Added some more guidelines and testing formatting
*README.md formatting for openTill.Testing
*README.md +exception to second style guideline
*README.md for openTill.Testing +more rules
*README.md for openTill.Testing [spelling]
*README.md for openTill.Testing rules for tests
Merge remote-tracking branch 'origin/sprint-1-Testing' into sprint-1