This PR migrates sloth from PyQt4 to PyQt5
It looks like Anaconda python distro can't have both PyQt4 and PyQt5 installed in parallel (at least I didn't find a way to coerce it into installing both side by side), and the distro itself depends on PyQt5. So, if I want any of the data scientists to be able to run sloth, I need this :)
This PR migrates sloth from PyQt4 to PyQt5 It looks like Anaconda python distro can't have both PyQt4 and PyQt5 installed in parallel (at least I didn't find a way to coerce it into installing both side by side), and the distro itself depends on PyQt5. So, if I want any of the data scientists to be able to run sloth, I need this :)