0.5.4

• Replace km.cleanup with km.cleanup_resources #152 (@davidbrochart)
• Use async generator backport only on old python #154 (@mkoeppe)
• Support parsing of IPython dev version #150 (@cphyc)
• Set IPYKERNEL_CELL_NAME = <IPY-INPUT> #147 (@davidbrochart)
• Print useful error message on exception #142 (@certik)