0.12.0 doesn't work with statsmodels 0.5.0
```
ols = pd.ols(y=portfolio_weights, x=alphas, intercept=intercept)
```

> ---
> 
> ImportError                               Traceback (most recent call last)
> <ipython-input-53-2a147656afb3> in <module>()
>       1 # Regress weights on alphas
> ----> 2 ols = pd.ols(y=portfolio_weights, x=alphas, intercept=intercept)
>       3 #ols = pd.ols(y=portfolio_weights, x=alphas, intercept=intercept, weights=weights)
>       4 print(ols.summary)
> 
> C:\Python27\lib\site-packages\pandas\stats\interface.pyc in ols(**kwargs)
>     133             klass = MovingOLS
>     134 
> --> 135     return klass(**kwargs)
> 
> C:\Python27\lib\site-packages\pandas\stats\ols.pyc in **init**(self, y, x, intercept, weights, nw_lags, nw_overlap)
>      51             import statsmodels.api as sm
>      52         except ImportError:
> ---> 53             import scikits.statsmodels.api as sm
>      54 
>      55         self._x_orig = x
> 
> ImportError: No module named scikits.statsmodels.api
