renamed tests to follow a different syntax. Before we would describe what
we were testing by saying the value, Thus, instead of saying small, we would
say 2 or whatever value it may be. We now describe the intend instead of
giving the value.

added tests and subsequently changed code to cover smaller values for
various classes
Extracted even palindrome builder
used even palindrom builder while changing solution4
used even palindrom builder while changing solution4, fixed a bug
deleted old unused code