Screenshots are invalid

[NetanelMosheCohen]

I'm using the latest version 1.1.1 and running the tests on MAC.

When add_screenshot bool is set to True, an invalid screenshot is attached to the report:

I tried to figure out why, and I saw that the attachment is sent with 'mime': 'application/octet-stream':

self.service.log_step_result(end_time=timestamp(),
message=error_msg,
level='ERROR',
attachment={
'name': step_name,
'data': open(screenshot_name, 'rb'),
'mime': 'application/octet-stream'
},
item_id=item_id
)

When I change it to 'mime': 'image/png' it works as expected: