Let fedora install redis 3.2

I think our existing code can only be installed in fedora redis2.8[1],
and our latest is to support redis3.2. These conclusions are only
tested in the virtual machine, there is no guarantee that the
image built with this will be available[2].

[1]:use dnf -y install redis
 will install this:
 redis-2.8.23-1.fc22.x86_64.rpm

[2]: After my experiment, can see
[root@localhost songjian]# redis-cli -v
redis-cli 3.2.8