Add first changes to syncing logic

- Adds testing framework
- Breaks out new `NetworkContext` object

beacon_node/libp2p/Cargo.toml

@@ -5,6 +5,7 @@ authors = ["Age Manning <Age@AgeManning.com>"]
 edition = "2018"
 
 [dependencies]
+beacon_chain =  { path = "../beacon_chain" }
 # SigP repository until PR is merged
 libp2p =  { git = "https://github.com/SigP/rust-libp2p", branch = "gossipsub" }
 types = { path =  "../../eth2/types" }