MXS-1300: Improve test coverage

The tests now cover 100% of all source files with the exception of the
call.js and common.js source files.

maxctrl/test/rotate.js

@@ -0,0 +1,12 @@
+require('../test_utils.js')()
+
+describe("Rotate Commands", function() {
+    before(startMaxScale)
+
+    it('rotate logs', function() {
+        return doCommand('rotate logs')
+            .should.be.fulfilled
+    });
+
+    after(stopMaxScale)
+});