Adding manager command with `init_script` fails

Versions
- Python 2.7.11
- Flask-Script 2.0.5
- Flask-Collect 1.3.2
- Flask 0.11.1

``` python
Traceback (most recent call last):
File "manage.py", line 12, in
from uiapp import app, models, db, manager
File "/Users/pavel/dev/my_proj/my_app/uiapp/__init__.py", line 22, in
collect.init_script(manager)
File "/Users/pavel/.virtualenvs/my_proj/lib/python2.7/site-packages/flask_collect/collect.py", line 119, in init_script
manager.command(collect_proxy)
File "/Users/pavel/.virtualenvs/my_proj/lib/python2.7/site-packages/flask_script/__init__.py", line 285, in command
command = Command(func)
File "/Users/pavel/.virtualenvs/my_proj/lib/python2.7/site-packages/flask_script/commands.py", line 118, in __init__
args, varargs, keywords, defaults = inspect.getargspec(func)
File "/Users/pavel/.pyenv/versions/2.7.11/lib/python2.7/inspect.py", line 816, in getargspec
raise TypeError('{!r} is not a Python function'.format(func))
TypeError: is not a Python function
```

As a workaround, I just added a call to `static`. Seems to work well:

``` python
# manage.py

@manager.command
def collect():
"""Collect static from blueprints."""

return current_app.extensions['collect'].collect()
```

EDIT: commit 9979f22 may have caused this.
##

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Start with flask_collect/collect.py around init_script, then inspect commit 9979f22 and compare it with the working manage.py workaround shown in the report. Reproduce the failure with the listed Python, Flask, Flask-Script, and Flask-Collect versions; done means init_script registers the manager command without the LocalProxy TypeError.

Written by the indexing model from the issue text.