fix(python3.7): update mathy_envs for typing fix (#80)

Author: justindujardin

libraries/mathy_python/requirements.txt

@@ -6,7 +6,7 @@ pydantic>=1.0.0
 typer<0.7.0,>=0.6.1
 wasabi
 mathy_core>=0.8.6,<0.9.0
-mathy_envs[gym]>=0.11.3,<0.12.0
+mathy_envs[gym]>=0.11.4,<0.12.0
 fragile==0.0.47
 tqdm>=4.43.0
 # new python feature backports