Wrap long line in README.md

Change-Id: I369bb6fa0539d350d5678f1d5d5defc78ded2d4e
diff --git a/README.md b/README.md
index f8b7169..4a61e1e 100644
--- a/README.md
+++ b/README.md
@@ -5,5 +5,6 @@
 
 This plugin uses [polymer-cli](https://www.polymer-project.org/1.0/docs/tools/polymer-cli#install) to test.
 
-After `bower install`, running `polymer test -l chrome` will run all tests in Chrome, and running `polymer serve` and navigating to http://127.0.0.1:8081/components/checks/gr-checks/gr-checks-view_test.html allows for manual debugging.
+After `bower install`, running `polymer test -l chrome` will run all tests in Chrome, and running `polymer serve`
+and navigating to http://127.0.0.1:8081/components/checks/gr-checks/gr-checks-view_test.html allows for manual debugging.