fix set_color_cycle from matplotlib deprecation warning

/usr/lib/python2.7/dist-packages/matplotlib/cbook.py:137: MatplotlibDeprecationWarning: The set_color_cycle attribute was deprecated in version 1.5. Use set_prop_cycle instead.
warnings.warn(message, mplDeprecation, stacklevel=1)

from ..toolchain_makefile import toolchain_makefile

class Generic_target(toolchain_makefile):
    pass