Remove substrate/node lib.rs

This shouldn't be used as a library AFAIK. While runtime should be, and 
arguably should even be published, I have yet to see node in the same 
way. Helps tighten API boundaries.

substrate/node/src/command.rs

@@ -117,7 +117,7 @@ pub fn run() -> sc_cli::Result<()> {
       }
 
       BenchmarkCmd::Extrinsic(cmd) => {
-        let PartialComponents { client, .. } = service::new_partial(&config)?;
+        let client = service::new_partial(&config)?.client;
         cmd.run(
           client.clone(),
           inherent_benchmark_data()?,

substrate/node/src/lib.rs

@@ -1,3 +0,0 @@
-pub mod chain_spec;
-pub mod rpc;
-pub mod service;