Added cardano-node

nix/sources.json

@@ -1,4 +1,16 @@
 {
+    "cardano-node": {
+        "branch": "ff-environment",
+        "description": "The core component that is used to participate in a Cardano decentralised blockchain.",
+        "homepage": "https://cardano.org",
+        "owner": "input-output-hk",
+        "repo": "cardano-node",
+        "rev": "bf8ab6e8e4468a8c3f6f4ea04f69314c057d6fb5",
+        "sha256": "0jk34cqbm6caxhw987gif4fxm4j3szzd1rhmxzbln90a97w7ypr4",
+        "type": "tarball",
+        "url": "https://github.com/input-output-hk/cardano-node/archive/bf8ab6e8e4468a8c3f6f4ea04f69314c057d6fb5.tar.gz",
+        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+    },
     "niv": {
         "branch": "master",
         "description": "Easy dependency management for Nix projects",