I have this error when I run tests on a conda environment which I built from specs in `environment.yml`

```
File "utils.py", line 5, in <module>
    import pycurl
ImportError: pycurl: libcurl link-time version (7.29.0) is older than compile-time version (7.55.1)

```

The environment.yml file used to build the conda env:

```
name: indices_python
channels:
- defaults
- conda-forge
dependencies:
- coverage 
- coveralls
- nco
- netcdf4
- nose
- numba
- numpy
- pandas
- pycurl
- pynco
- python=3
- scipy

```

The command I'm running (on Linux):

```
$ python -W ignore -m unittest tests/test_*.py

```

How can I fix this and/or how to prevent this from happening in the future?