BUG: fix handling of color argument for variety of plotting functions

parallel_coordinates
- fix reordering of class column (from set) causing possible color/class
  mismatch
- deprecated use of argument colors in favor of color
radviz
- fix reordering of class column (from set) causing possible color/class
  mismatch
- added explicit color keyword argument (avoids multiple values 'color' being
  passed to plotting method)
andrews_curves
- added explicit color keyword argument (avoids multiple values 'color' being
  passed to plotting method)
TST: add tests for deprecation warnings from plotting functions

parallel_coordinates/andrews_curves
- added deprecate_kwarg decorator for using frame argument instead of data
- added tests to check that FutureWarning is raised properly