Upgrade elastic-array to 0.9.0

This is a huge change, which includes some changes to replace code that
originally cloned to reuse allocations instead. The updated
`elastic-array` crate renames its consuming `Vec`-conversion method to
`into_vec`, which means that I can do a simple
`sed -i 's/to_vec/into_vec/'` and then fix the compilation errors.

This commit is probably a minor performance win and definitely a
significant readability win.

stratum/src/lib.rs

@@ -342,7 +342,7 @@ mod tests {
 		let mut core = Core::new().expect("Tokio Core should be created with no errors");
 		let mut buffer = vec![0u8; 2048];
 
-		let mut data_vec = data.as_bytes().to_vec();
+		let mut data_vec = data.as_bytes().into_vec();
 		data_vec.extend(b"\n");
 
 		let stream = TcpStream::connect(addr, &core.handle())
@@ -353,7 +353,7 @@ mod tests {
 				io::read(stream, &mut buffer)
 			})
 			.and_then(|(_, read_buf, len)| {
-				future::ok(read_buf[0..len].to_vec())
+				future::ok(read_buf[0..len].into_vec())
 			});
 			let result = core.run(stream).expect("Core should run with no errors");
 
@@ -454,7 +454,7 @@ mod tests {
 		let mut auth_request =
 			r#"{"jsonrpc": "2.0", "method": "mining.authorize", "params": ["miner1", ""], "id": 1}"#
 			.as_bytes()
-			.to_vec();
+			.into_vec();
 		auth_request.extend(b"\n");
 
 		let mut core = Core::new().expect("Tokio Core should be created with no errors");
@@ -487,7 +487,7 @@ mod tests {
 			})
 			.and_then(|(_, read_buf, len)| {
 				trace!(target: "stratum", "Received work from server");
-				future::ok(read_buf[0..len].to_vec())
+				future::ok(read_buf[0..len].into_vec())
 			});
 		let response = String::from_utf8(
 			core.run(stream).expect("Core should run with no errors")