Make broadcaster dependencies optional

An option is available for each backend as well as an "all" option which gets you everything.

Author: nneskildsf

requirements.txt

@@ -1,5 +1,4 @@
 fastapi-websocket-rpc>=0.1.25,<1
 packaging>=20.4
-permit-broadcaster[redis,postgres,kafka]>=0.2.5,<3
 pydantic>=1.9.1
 websockets>=10.3

setup.py

@@ -30,4 +30,10 @@ def get_requirements(env=""):
     ],
     python_requires=">=3.9",
     install_requires=get_requirements(),
+    extras_require = {
+        "redis": ["permit-broadcaster[redis]>=0.2.5,<3"],
+        "postgres": ["permit-broadcaster[postgres]>=0.2.5,<3"],
+        "kafka": ["permit-broadcaster[kafka]>=0.2.5,<3"],
+        "all": ["permit-broadcaster[redis,postgres,kafka]>=0.2.5,<3"],
+    }
 )