[lib] Require a recent version of pip

library/setup.py

@@ -133,6 +133,7 @@ setup(
     description="Cadbiom library",
     long_description=open('README.md').read(),
     install_requires=[
+        "pip>=20.0",
         "networkx<2", "lxml",
         "pycryptosat>0.1.2", "antlr3-python-runtime==3.4",
         "cached-property>=1.5,<1.6",