horizon.d: msgpack not listest as a depencency

[gregswift]

[root@skyline-n01 bin]# ./horizon.d start
rm: cannot remove ‘../src/horizon/*.pyc’: No such file or directory
Traceback (most recent call last):
File "../src/horizon/horizon-agent.py", line 13, in
from listen import Listen
File "/root/skyline-master/src/horizon/listen.py", line 6, in
from msgpack import unpackb
ImportError: No module named msgpack
failed to start horizon-agent

[astanway]

See #26