Merge pull request #20 from tlpinney/master

Added documentation on installing dependencies
Merge pull request #21 from tlpinney/master

Add requirements.txt and add info on installing virtualenv
Move out of appendBuilding().
Merge pull request #22 from tlpinney/master

Case-sensitive fix
Dedupe nodes, addresses #11. Slow.
Speed up 100X.
merge.
Add gitignore
Merge branch 'master' of github.com:tlpinney/dcbuildings
Added script to pull out building information of dc buildings to be used for analysis in R