[BUG] importing pysindy adds "Ignore UserWarning" to the global warnings filter

[Jacob-Stevens-Haas]

As title. Should be a simple fix, but this is a placeholder to come back to it.

Reproducing code example:

import pysindy
import warnings
warnings.warn("Foo", UserWarning)
warnings.filters[0]

Error message:

None, no warnings appear. Filter is ('ignore', None, UserWarning, None, 0)

PySINDy/Python version information:

master