Find new way to retrieve position list #182
Description
In the original implementation of shrimpy, the user would set positions to be imaged using the MicroManager GUI (aka Studio) and we would retrieve those trough the pycromanager interface for the Studio. After we find a replacement for the GUI (#174) we'll update the way we fetch the position list and remove references to the Studio. Before we find a replacement GUI, it's OK to use workarounds such as loading the position list from file or hardcoding it somewhere.