json problem in api.py

When I try to run the program, I get this error:

```
RuntimeError: module compiled against API version 0xa but this version of numpy is 0x9
Traceback (most recent call last):
File "api.py", line 33, in
import matplotlib.pyplot as plt
File "/home/crash/TestEnv/venv/local/lib/python2.7/site-packages/matplotlib/pyplot.py", line 27, in
import matplotlib.colorbar
File "/home/crash/TestEnv/venv/local/lib/python2.7/site-packages/matplotlib/colorbar.py", line 32, in
import matplotlib.artist as martist
File "/home/crash/TestEnv/venv/local/lib/python2.7/site-packages/matplotlib/artist.py", line 12, in
from .transforms import Bbox, IdentityTransform, TransformedBbox, \
File "/home/crash/TestEnv/venv/local/lib/python2.7/site-packages/matplotlib/transforms.py", line 39, in
from matplotlib._path import (affine_transform, count_bboxes_overlapping_bbox,
ImportError: numpy.core.multiarray failed to import
```

I then tried to update numpy to the most recent version, which leads to this error:

```
Traceback (most recent call last):
File "api.py", line 340, in
if __name__ == '__main__': main()
File "api.py", line 286, in main
opts = parse_args()
File "api.py", line 274, in parse_args
help='Path to the PNG file which should contain the data output')
File "/usr/lib/python2.7/argparse.py", line 1297, in add_argument
return self._add_action(action)
File "/usr/lib/python2.7/argparse.py", line 1671, in _add_action
self._optionals._add_action(action)
File "/usr/lib/python2.7/argparse.py", line 1498, in _add_action
action = super(_ArgumentGroup, self)._add_action(action)
File "/usr/lib/python2.7/argparse.py", line 1311, in _add_action
self._check_conflict(action)
File "/usr/lib/python2.7/argparse.py", line 1449, in _check_conflict
conflict_handler(action, confl_optionals)
File "/usr/lib/python2.7/argparse.py", line 1456, in _handle_conflict_error
raise ArgumentError(action, message % conflict_string)
argparse.ArgumentError: argument --plot-file: conflicting option string(s): --plot-file
```

I tried it using my code, and then I tried it using the code on here, but either way I get the same issue.