Added HWE calculations

Added calculations for Hardy Weinberg Equilibrium expected values, chi squared value, and a boolean value for significance.
Added HWE calculations

Added calculations for Hardy Weinberg Equilibrium expected values, chi squared, and a boolean value for p-value significance with 2 degrees of freedom at the 0.05 level.
Fixed a bug that messed up the tables.
Made some changes to match the original.
Made code more succinct with subqueries.

Made code a little more elegant.  Calculations are the same but they are cleaner and easier to read.
Updated md file to match changes in query
Merge pull request #5 from gregmcinnes/qc-codelab

Updated qc demo to include HWE calculations