use of pickle newer protocol versions #115
Description
In the microscope.deviceserver and microscope.clients we hardcode requirement of pickle protocol version 2. The latest is version 5 which claims better performance for larger data and newer python types. Is there a reason why we force protocol version 2?
Looking in the history, I found it was added with b9e5c1c a commit that adds support for python 3. Because protocol versions above 2 do not support Python 2, I'm guessing this was done in order to keep supporting python 2. Since we no longer support Python 2, I guess we can remove it.