chore(keyboard): remove legacy key binding exports

BREAKING CHANGES:

* Key binding exports exposed by `KeyboardBindings` removed in
  favor of `KeyboardUtil` utilities

lib/features/keyboard/KeyboardBindings.js

@@ -9,11 +9,12 @@ import {
 
 var LOW_PRIORITY = 500;
 
-export var KEYCODE_C = 67;
-export var KEYCODE_V = 86;
-export var KEYCODE_Y = 89;
-export var KEYCODE_Z = 90;
+var KEYCODE_C = 67;
+var KEYCODE_V = 86;
+var KEYCODE_Y = 89;
+var KEYCODE_Z = 90;
 
+// TODO(nikku): remove in future diagram-js version
 export var KEYS_COPY = [ 'c', 'C', KEYCODE_C ];
 export var KEYS_PASTE = [ 'v', 'V', KEYCODE_V ];
 export var KEYS_REDO = [ 'y', 'Y', KEYCODE_Y ];

test/spec/features/keyboard/KeyboardBindingsSpec.js

@@ -0,0 +1,18 @@
+import {
+  KEYS_UNDO,
+  KEYS_REDO,
+  KEYS_COPY,
+  KEYS_PASTE
+} from 'lib/features/keyboard/KeyboardBindings';
+
+
+describe('features/keyboard - KeyboardBindings', function() {
+
+  it('should provide legacy KEYS_* exports', function() {
+    expect(KEYS_UNDO).to.exist;
+    expect(KEYS_REDO).to.exist;
+    expect(KEYS_COPY).to.exist;
+    expect(KEYS_PASTE).to.exist;
+  });
+
+});