queue/redis: cleanup the queue on SetUpSuite
queue/redis: cleanup the queue on SetUpSuite

Each test should clean its mess, as in the beanstalkd suite.

gciotta/tsuru,hcxiong/tsuru,tsuru/tsuru,cgvarela/tsuru,guilhermebr/tsuru,cezarsa/tsuru,hugoantunes/tsuru,firebitsbr/tsuru,kgrvamsi/tsuru,guilhermebr/tsuru,4eek/tsuru,tuxmonteiro/tsuru,cgvarela/tsuru,Endika/tsuru,gwmoura/tsuru,RichardKnop/tsuru,mderaldo/tsuru,tsuru/tsuru,4eek/tsuru,tsuru/tsuru,ggarnier/tsuru,guilhermebr/tsuru,ArxdSilva/tsuru,firebitsbr/tsuru,gciotta/tsuru,cezarsa/tsuru,jblancett/tsuru,RichardKnop/tsuru,jblancett/tsuru,firebitsbr/tsuru,ArxdSilva/tsuru,mderaldo/tsuru,hcxiong/tsuru,cezarsa/tsuru,ggarnier/tsuru,guilhermebr/tsuru,gwmoura/tsuru,cezarsa/tsuru,gwmoura/tsuru,jblancett/tsuru,ggarnier/tsuru,tuxmonteiro/tsuru,hcxiong/tsuru,4eek/tsuru,cgvarela/tsuru,hugoantunes/tsuru,ggarnier/tsuru,ArxdSilva/tsuru,mderaldo/tsuru,kgrvamsi/tsuru,ArxdSilva/tsuru,tuxmonteiro/tsuru,gciotta/tsuru,Endika/tsuru,tsuru/tsuru,RichardKnop/tsuru,Endika/tsuru,kgrvamsi/tsuru