Add pickling test
Add pickling test

jparyani/pycapnp,tempbottle/pycapnp,jparyani/pycapnp,rcrowder/pycapnp,SymbiFlow/pycapnp,rcrowder/pycapnp,tempbottle/pycapnp,rcrowder/pycapnp,tempbottle/pycapnp,SymbiFlow/pycapnp,jparyani/pycapnp,SymbiFlow/pycapnp,tempbottle/pycapnp,SymbiFlow/pycapnp,jparyani/pycapnp,rcrowder/pycapnp