Add users.isActivated

it's easier to see where we do activation checks

src/users.js

@@ -8,7 +8,7 @@ exports = module.exports = {
 
     list: list,
     create: create,
-    count: count,
+    isActivated: isActivated,
     verify: verify,
     verifyWithUsername: verifyWithUsername,
     verifyWithEmail: verifyWithEmail,
@@ -323,6 +323,16 @@ function count(callback) {
     });
 }
 
+function isActivated(callback) {
+    assert.strictEqual(typeof callback, 'function');
+
+    count(function (error, count) {
+        if (error) return callback(error);
+
+        callback(null, count !== 0);
+    });
+}
+
 function get(userId, callback) {
     assert.strictEqual(typeof userId, 'string');
     assert.strictEqual(typeof callback, 'function');