Fix explicit access

src/public/AddonManager.test.ts

@@ -24,11 +24,11 @@ describe('AddonManager', () => {
     it('should call addon constructor', () => {
       let called = false;
       class Addon implements ITerminalAddon {
-        activate(terminal: any): void {
+        public activate(terminal: any): void {
           assert.equal(terminal, 'foo', 'The first constructor arg should be Terminal');
           called = true;
         }
-        dispose(): void { }
+        public dispose(): void { }
       }
       manager.loadAddon('foo' as any, new Addon());
       assert.equal(called, true);
@@ -39,8 +39,8 @@ describe('AddonManager', () => {
     it('should dispose all loaded addons', () => {
       let called = 0;
       class Addon implements ITerminalAddon {
-        activate(): void {}
-        dispose(): void { called++; }
+        public activate(): void {}
+        public dispose(): void { called++; }
       }
       manager.loadAddon(null, new Addon());
       manager.loadAddon(null, new Addon());