Fixed failing coroutine test (test was written incorrectly)

[prologic]

Test passes:

#!bash
$ py.test -x -s -v tests/core/test_coroutine.py 
================================================= test session starts ==================================================
platform linux2 -- Python 2.7.9 -- py-1.4.27 -- pytest-2.7.0 -- /home/prologic/.virtualenvs/circuits/bin/python
rootdir: /home/prologic/work/circuits, inifile: 
plugins: cov
collected 1 items 

tests/core/test_coroutine.py::test_coroutine <registered[*] (<Debugger/* 14267:Manager (queued=0) [S]>, <Manager/ 14267:Manager (queued=3) [R]> )>
<registered[*] (<Watcher/* 14267:Manager (queued=0) [S]>, <Manager/ 14267:Manager (queued=2) [R]> )>
<registered[*] (<App/* 14267:Manager (queued=0) [S]>, <Manager/ 14267:Manager (queued=1) [R]> )>
<coroutine1[*] ( )>
coroutine1
<test[*] ( )>
<test_done[*] ('Hello World!' )>
returned
<coroutine1_complete[*] (<coroutine1[*] ( )>, None )>
<coroutine2[*] ( )>
coroutine2
<test[*] ( )>
<test_done[*] ('Hello World!' )>
returned
<coroutine2_complete[*] (<coroutine2[*] ( )>, None )>
PASSED<prepare_unregister[*] (<App/* 14267:Manager (queued=0) [S]> )>
<prepare_unregister[*] (<Watcher/* 14267:Manager (queued=0) [S]> )>
<prepare_unregister_complete[<App/* 14267:Manager (queued=0) [S]>] (<prepare_unregister[*] (<App/* 14267:Manager (queued=0) [S]> )>, None )>
<prepare_unregister_complete[<Watcher/* 14267:Manager (queued=0) [S]>] (<prepare_unregister[*] (<Watcher/* 14267:Manager (queued=0) [S]> )>, None )>
<unregistered[*] (<App/* 14267:Manager (queued=0) [S]>, <Manager/ 14267:Manager (queued=2) [R]> )>
<unregistered[*] (<Watcher/* 14267:Manager (queued=0) [S]>, <Manager/ 14267:Manager (queued=1) [R]> )>


=============================================== 1 passed in 1.03 seconds ===============================================