PHATE v0.2.9

Changes:

• Use tasklogger for logging; fixes issues with Windows 7 verbose output
• Use scprep in tutorials for simpler analysis
• Change default value of alpha to 40 for faster computation of kernel
• phate.plot.scatter now takes keyword arguments x, y and z rather than a list-like
• phate.plot.scatter has keyword arguments for axis label prefix label_prefix (as an alternative to labelling axes individually), plot title title, and legend location legend_loc
• minor bugfixes