remove stokes_slip_bc_penalty.py example
remove stokes_slip_bc_penalty.py example

BubuLK/sfepy,rc/sfepy,sfepy/sfepy,rc/sfepy,BubuLK/sfepy,sfepy/sfepy,vlukes/sfepy,vlukes/sfepy,BubuLK/sfepy,rc/sfepy,sfepy/sfepy,vlukes/sfepy