Bug in module source reading

```
During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/home/bot/bot/venv/lib/python3.6/site-packages/aiohttp/web_protocol.py", line 417, in start
resp = yield from self._request_handler(request)
File "/home/bot/bot/venv/lib/python3.6/site-packages/aiohttp/web.py", line 289, in _handle
resp = yield from handler(request)
File "/home/bot/bot/applications/github/github/sdk/lib/server.py", line 31, in wrapper
self.sdk.hawk.catch()
File "/home/bot/bot/venv/lib/python3.6/site-packages/hawkcatcher/__init__.py", line 108, in catch
self.handler(*sys.exc_info())
File "/home/bot/bot/venv/lib/python3.6/site-packages/hawkcatcher/__init__.py", line 80, in handler
callee['sourceCode'] = self.get_near_filelines(callee['file'], callee['line'])
File "/home/bot/bot/venv/lib/python3.6/site-packages/hawkcatcher/__init__.py", line 120, in get_near_filelines
with open(filepath, 'r') as file:
FileNotFoundError: [Errno 2] No such file or directory: '/home/bot/bot/applications/github/github/multidict/_multidict.pyx'
```