reactor: rename tokio-reactor -> tokio-net (#1450)

* reactor: rename tokio-reactor -> tokio-net

This is in preparation for #1264

ui-tests/tests/features.rs

@@ -1,9 +1,22 @@
 #[test]
-fn features() {
+#[cfg(feature = "tokio-with-net")]
+#[allow(unused_imports)]
+fn tokio_with_net() {
+    // Reactor is present
+    use ui_tests::tokio::reactor;
+
+    // net is present
+    use ui_tests::tokio::net;
+}
+#[test]
+fn compile_fail() {
     let t = trybuild::TestCases::new();
 
     #[cfg(feature = "executor-without-current-thread")]
     t.compile_fail("tests/ui/executor_without_current_thread.rs");
 
+    #[cfg(feature = "tokio-no-features")]
+    t.compile_fail("tests/ui/tokio_without_net_missing_reactor.rs");
+
     drop(t);
 }