Initial Interop Updates (#492)

* Add interop chain spec and rename chain_id

* Add ability to connect to raw libp2p nodes

* Adds Identify protocol, clean up RPC protocol name handling

* Update to latest libp2p, gossipsub improvements

* Updates to latest interop branch.

- Shifts decoding of objects into message handler.
- Updates to latest interop gossipsub.
- Adds interop spec constant.

* Configuration updates allow for verbosity CLI flag and spec constants

* Update submodules to master

* Correct minimal chainspec modifications

* Duplication of validator polls are no longer fatal

* Apply PR suggestions

eth2/utils/eth2_config/src/lib.rs

@@ -37,6 +37,13 @@ impl Eth2Config {
             spec: ChainSpec::minimal(),
         }
     }
+
+    pub fn interop() -> Self {
+        Self {
+            spec_constants: "interop".to_string(),
+            spec: ChainSpec::interop(),
+        }
+    }
 }
 
 impl Eth2Config {