adds Bank TDD example
day_5
Merge branch 'master' of https://github.com/schechter/MTR
removes 'def customer_interface.rb
pulling updated stock portfolio
Merge branch 'master' of https://github.com/schechter/MTR
pulling updated stock portfolio
adds lots of tests.  Still one failing I can't figure out right now. getting error I dont' want to look at any more right now.