Default boot_nodes to local node in build-spec (#1181)

* Default to local bootnode with build-spec

* Rexport libp2p stuff via network crate

* Remove unused imports and fix where formatting

* Remove spurious blank lines

* Remove unnecessary else clause

substrate/core/service/src/chain_spec.rs

@@ -23,6 +23,7 @@ use primitives::storage::{StorageKey, StorageData};
 use runtime_primitives::{BuildStorage, StorageMap, ChildrenStorageMap};
 use serde_json as json;
 use components::RuntimeGenesis;
+use network::Multiaddr;
 
 enum GenesisSource<G> {
 	File(PathBuf),
@@ -139,6 +140,10 @@ impl<G: RuntimeGenesis> ChainSpec<G> {
 		self.spec.properties.as_ref().unwrap_or(&json::map::Map::new()).clone()
 	}
 
+	pub fn add_boot_node(&mut self, addr: Multiaddr) {
+		self.spec.boot_nodes.push(addr.to_string())
+	}
+
 	/// Parse json content into a `ChainSpec`
 	pub fn from_embedded(json: &'static [u8]) -> Result<Self, String> {
 		let spec = json::from_slice(json).map_err(|e| format!("Error parsing spec file: {}", e))?;