Update setup.py

Author: Marin Bilos

requirements.txt

@@ -4,4 +4,8 @@
       version='0.1.0',
       description='normalizing flows and neural flows',
       packages=find_packages('.'),
-      zip_safe=False)
+      packages=setuptools.find_packages(),
+      install_requires=['numpy>=1.20.1', 'torch>=1.8.0', 'torchdiffeq==0.2.1']
+      python_requires='>=3.6',
+      zip_safe=False
+)