Since the release of `gym==0.25.0`, `gym_guppy` tests are failing with: ``` ImportError while loading conftest '/builds/bioroboticslab/robofish/gym-guppy/tests/conftest.py'. tests/conftest.py:2: in <module> from robofish.gym_guppy.envs import GuppyEnv /usr/lib/python3.8/site-packages/robofish/gym_guppy/__init__.py:4: in <module> from .envs import GuppyEnv, GoalGuppyEnv, VariableStepGuppyEnv, VariableStepGoalGuppyEnv /usr/lib/python3.8/site-packages/robofish/gym_guppy/envs/__init__.py:21: in <module> from ._guppy_env import GuppyEnv /usr/lib/python3.8/site-packages/robofish/gym_guppy/envs/_guppy_env.py:25: in <module> class GuppyEnv(gym.Env, metaclass=abc.ABCMeta): E TypeError: metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases ``` `gym==0.24.1` is the last version that works.