* fix(challenges): Update challenge text and assertion test
* fix(challenges): update assert test regex
* fix(challenges): update regex, fix inline comment in code example
* fix: corrected regex
Original: "Your code should create a method in Bird called getWeight that returns the weight".
New: "Your code should create a method in Bird called getWeight that returns the weight 15".
Since 15 is the only current passing value I feel it should be plainly stated instead in the test case.
