Description:
I get an import error when I try to import numpy in a simple python instance. It seems to try opening a missing shared file `libgfortran.so.3`.
I see that there is a file installed `libgfortran.so.4`.

Additional info:
* package version(s)
* python: 3.6.1-1
* python-numpy: 1.13.0-1
* gcc-fortran: 7.1.1-3

* traceback of the error:
Traceback (most recent call last):
File "/usr/lib/python3.6/site-packages/numpy/core/__init__.py", line 16, in <module>
from . import multiarray
ImportError: libgfortran.so.3: cannot open shared object file: No such file or directory

During handling of the above exception, another exception occurred:

```
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python3.6/site-packages/numpy/__init__.py", line 142, in <module>
from . import add_newdocs
File "/usr/lib/python3.6/site-packages/numpy/add_newdocs.py", line 13, in <module>
from numpy.lib import add_newdoc
File "/usr/lib/python3.6/site-packages/numpy/lib/__init__.py", line 8, in <module>
from .type_check import *
File "/usr/lib/python3.6/site-packages/numpy/lib/type_check.py", line 11, in <module>
import numpy.core.numeric as _nx
File "/usr/lib/python3.6/site-packages/numpy/core/__init__.py", line 26, in <module>
raise ImportError(msg)
ImportError:
Importing the multiarray numpy extension module failed. Most
likely you are trying to import a failed build of numpy.
If you're working with a numpy git repo, try `git clean -xdf` (removes all
files not under version control). Otherwise reinstall numpy.

Original error was: libgfortran.so.3: cannot open shared object file: No such file or directory

```

Steps to reproduce:
Install python-numpy with pacman:

python -S python-numpy

Open python and try importing numpy.