Implemented the Print methods for Printables and String and re-implemented the print number methods.
Re-implemented the print methods for integers and longs so that they take base
Re-implemented the print methods for doubles so that it takes a digit parameter
Added PrintTests to test folder
Fixed the DigitalPin tests to use the latest SDK NuGet
Merge pull request #19 from anthony-ngu/AddingPrintImplementation

Implemented the Print methods for Printables and String