Removed nose dependency in callback_test.py. Feel free to run the tests w/ nose on the CLI if you like, but it's not used in the *writing* of the tests.
Removed nose dependency in callback_test.py. Feel free to run the tests w/ nose on the CLI if you like, but it's not used in the *writing* of the tests.

skftn/pika,renshawbay/pika-python3,zixiliuyue/pika,vrtsystems/pika,benjamin9999/pika,hugoxia/pika,pika/pika,Zephor5/pika,knowsis/pika,reddec/pika,jstnlef/pika,vitaly-krugl/pika,shinji-s/pika,fkarb/pika-python3,Tarsbot/pika