redis bitcount example not working

Question

I was playing with redis and tried the bitcount example: http://redis.io/commands/bitcount .

127.0.0.1:6379> SET mykey "foobar"
OK
127.0.0.1:6379> BITCOUNT mykey
(error) ERR unknown command 'BITCOUNT'

my redis version are as follows:

mohit@mohit:~$ redis-server --version
Redis server v=3.0.1 sha=00000000:0 malloc=jemalloc-3.6.0 bits=64 build=ecf41ef76feca5d
mohit@mohit:~$ redis-cli --version
redis-cli 3.0.1

I verified with the website, 3.0.1 is the latest stable version. What went wrong in this arrangement?