Add tests for 1pass client app

Use python and the pexpect module to drive
the test client.
Add Makefile

This provides a 'make test' target which runs both the
go tests and the Python tests
Make -vault take precedence over the 'path' argument for the 'new' command

If '1pass' is invoked with a 'new' argument, use the value of the
'-vault' argument if supplied as the vault path instead of the
path argument.