Testnet compatible network upgrade (#587)

* Create libp2p instance

* Change logger to stdlog

* test_connection initial commit

* Add gossipsub test

* Delete tests in network crate

* Add test module

* Clean tests

* Remove dependency on discovery

* Working publish between 2 nodes
TODO: Publish should be called just once

* Working 2 peer gossipsub test with additional events

* Cleanup test

* Add rpc test

* Star topology discovery WIP

* build_nodes builds and connects n nodes. Increase nodes in gossipsub test

* Add unsubscribe method and expose reference to gossipsub object for gossipsub tests

* Add gossipsub message forwarding test

* Fix gossipsub forward test

* Test improvements
* Remove discovery tests
* Simplify gossipsub forward test topology
* Add helper functions for topology building

* Clean up tests

* Update naming to new network spec

* Correct ssz encoding of protocol names

* Further additions to network upgrade

* Initial network spec update WIP

* Temp commit

* Builds one side of the streamed RPC responses

* Temporary commit

* Propagates streaming changes up into message handler

* Intermediate network update

* Partial update in upgrading to the new network spec

* Update dependencies, remove redundant deps

* Correct sync manager for block stream handling

* Re-write of RPC handler, improves efficiency and corrects bugs

* Stream termination update

* Completed refactor of rpc handler

* Remove crates

* Correct compile issues associated with test merge

* Build basic tests and testing structure for eth2-libp2p

* Enhance RPC tests and add logging

* Complete RPC testing framework and STATUS test

* Decoding bug fixes, log improvements, stream test

* Clean up RPC handler logging

* Decoder bug fix, empty block stream test

* Add BlocksByRoot RPC test

* Add Goodbye RPC test

* Syncing and stream handling bug fixes and performance improvements

* Applies discv5 bug fixes

* Adds DHT IP filtering for lighthouse - currently disabled

* Adds randomized network propagation as a CLI arg

* Add disconnect functionality

* Adds attestation handling and parent lookup

* Adds RPC error handling for the sync manager

* Allow parent's blocks to be already processed

* Update github workflow

* Adds reviewer suggestions

beacon_node/src/cli.rs

@@ -221,6 +221,13 @@ pub fn cli_app<'a, 'b>() -> App<'a, 'b> {
                     .help("If present, append a random string to the datadir path. Useful for fast development \
                           iteration.")
             )
+            .arg(
+                Arg::with_name("random-propagation")
+                    .long("random-propagation")
+                    .value_name("INTEGER")
+                    .takes_value(true)
+                    .help("Specifies (as a percentage) the likelihood of propagating blocks and attestations. This should only be used for testing networking elements. The value must like in the range 1-100.")
+            )
             .arg(
                 Arg::with_name("force")
                     .long("force")