Removed Zombies directory
Merge branch 'develop' of git://github.com/byuimpact/numerical_computing into develop

Conflicts:
	Vol4.tex
Modified Vol4.tex
Added lab on Heat Equation
Merge branch 'develop' of git://github.com/byuimpact/numerical_computing into develop

Updating develop branch
Added SIR lab and first Pseudospectral lab
Modify Vol4.tex
Modified Vol4.tex
Merge pull request #556 from joshualy/develop

Added labs on the heat equation, SIR models, and the pseudospectral method.