Improve database testing

See merge request !46

This allows to more easily understand why the test fails if
the database object encounters error on creation.

Fix remove deprecated script

See merge request !45

Fix issue related to mixing click functions and other class functions

See merge request !44

Add option to make experiment run less verbose

See merge request !43

Handle case where CPU stats return 0

See merge request !42

This may happen if the container ran on GPU.

Fix click commands

See merge request !41

Fixes #40

Also cleans up all the sys.exit calls.

Also cleans up all the sys.exit calls.

This also cleans up all the sys.exit calls.

Click turns functions into "commands" which has the following consequences:
- Any return statement means that it has succeeded whatever the value returned
  therefore the exit code will be 0
- To "fail" properly an exception must be raised which will return an exit
  code of 1
- Other exceptions will be treated as usage error and have an exit code
  of 2

The raise_on_error decorator will take the returned value of the wrapped
function and raise a generic error with the exit code set to what the
function has returned.

Add missing platform parameter when calling API

See merge request !40

Add missing click dependency

See merge request !39

use click for command lines

See merge request !25

Fix doc extra marker

See merge request !38