Devices GET, POST, PUT DELETE

Closed as being duplicate of !31 (merged). Copied DB and API details to other issue.

Added new endpoints sonador/devices for GET AND POST sonador/devices/uid for PUT AND DELETE

DEVICE DB TABLE

op.create_table('sonador_devices', sa.Column('uid', sa.String(length=64), primary_key=True, unique=True), sa.Column('ctime', sa.DateTime()), sa.Column('mtime', sa.DateTime()), sa.Column('imaging_center', sa.String(length=64)), sa.Column('manufacturer', sa.String(length=64)), sa.Column('model_number', sa.String(length=64)), sa.Column('software_version', sa.String(length=64)), )