FEAT: start enpkg_machine_cli, for canopy platform.
REF: move repository names -> config setup in Configuration class.
FEAT: add repository support in machine cli install.
FEAT: add support for store_url in machine cli install.
FEAT: add support for files_cache in machine cli install.
FEAT: add remove command to machine cli.
FEAT: add update_all to machine cli.
TST: add basic tests for invalid json data.
MAINT: rename enpkg_machine_cli -> _enpkg_machine_cli.
BUG: hack to fix testing on 2.6.
REF: remove entry point for machine_cli.

We use `python -m enstaller.machine_cli` (
`python -m enstaller.machine_cli.__main__` if python 2.6 compat is
required).
ENH: pass data through stdin in machine_cli.
BUG: fix python 3 support in machine_cli.
FEAT: add API for subprocess protocol.
ENH: add support for any auth kind in machine_cli + doc.
Merge pull request #426 from enthought/machine_cli

Machine cli
REF: consolidate args serialization.
FEAT: add support for verify_ssl and proxy in machine_cli protocol.
BUG: fix testing to not depend on dict ordering.
Merge pull request #429 from enthought/add_missing_settings_machine_cli

Add missing settings machine cli