Path to 1.0

The following outlines the minimal features needed before I will consider tagging a 1.0 release.

1. Ability to add and edit inventory.

2. Ability to complete a transaction.

3. After a transaction is complete a drawer push is activated and a receipt is printed.

4. Ability to end a shift.

5. After a shift has completed an "end-of-shift" report is printed.

6. A reasonable amount of testing a bug squashing has been performed.