Merge pull request #69 from KellyBlack/black_dev

Updates to the discussion on partial fractions
Merge pull request #70 from KellyBlack/black_dev

Updated the first day of the laplace transform
delete the extra the on notes for laplace
Merge pull request #40 from guangmingyao/yao_dev

Yao dev
Merge remote-tracking branch 'origin/yao_dev' into black_dev