A bunch of tweaks to the Users directory

- Move user directory from `/directory` to `/users/`
- Defaults to 'weekly' time period
- Don't include deleted topics/posts in the results
- Move heart icon to header instead of on each row
- "Users" instead of "Users found"

test/javascripts/integration/users-test.js.es6

@@ -1,7 +1,7 @@
 integration("User Directory");
 
-test("Visit Page", () => {
-  visit("/directory/all");
+test("Visit Page", function() {
+  visit("/users");
   andThen(() => {
     ok(exists('.directory table tr'), "has a list of users");
   });