Refactor to actually be useful as a library

[achow101]

Refactors command.py so that it just has the functions for each command and the arguments are the actual arguments for the command instead of args and client. process_commands has been moved to cli.py along with the handlers that take args and client which then call the functions in commands.py to do the command.

setup.py has been updated to also install a hwi executable script and the version number is bumped to 0.0.5.

This makes HWI actually usable as a library while also having the command line functionality.

Completes part 1 of #91

[achow101]

Had to rebase

[instagibbs]

failing:

0.36s$ cd test; ./run_tests.py
Traceback (most recent call last):
  File "./run_tests.py", line 13, in <module>
    from test_ledger import ledger_test_suite
  File "/home/travis/build/achow101/HWI/test/test_ledger.py", line 15, in <module>
    from hwilib.commands import process_commands
ImportError: cannot import name 'process_commands'

[achow101]

Fixed the error

[Sjors]

Concept ACK. But let's use named arguments, especially for getkeypool(client, args.path, args.start, args.end, args.internal, args.keypool, args.account, args.sh_wpkh, args.wpkh). That makes it easier for me in #73 to pass in a descriptor, without having to explicitly set the positional args.path, args.sh_wpkh, etc to None.

[achow101]

Do you mean give each argument a default value or do you mean having the call be getkeypool(client=client, path=args.path, start=args.start, ...)?

[Sjors]

The latter. It's probably fine to keep some arguments like client positional.

[achow101]

@Sjors Done.

[Sjors]

Travis unhappy:

error: click 6.7 is installed but click<8,>=7 is required by {'trezor'}
The command "python setup.py install" failed and exited with 1 during .

[achow101]

Seems like a spurious failure. I restarted the travis build and it seems fine now

[Sjors]

tACK 8e4b3fc (based on testing #73, which I just rebased)