Use removeListener instead of off for Node 8

src/shared/TypedEmitter.test.ts

@@ -60,10 +60,10 @@ describe('TypedEmitter', () => {
     })
   })
 
-  describe('removeListener & off', () => {
+  describe('removeListener', () => {
     it('removes an event listener', () => {
       emitter.removeListener('test1', listener1)
-      emitter.off('test2', listener2)
+      emitter.removeListener('test2', listener2)
       emitter.emit('test1', 'value')
       emitter.emit('test2', 3)
       expect(stringMock.mock.calls).toEqual([])

src/shared/TypedEmitter.ts

@@ -19,7 +19,5 @@ export interface TypedEmitter<E extends Events> {
   on<K extends keyof E>(t: K, callback: Callback<E[K]>): this
   once<K extends keyof E>(t: K, callback: Callback<E[K]>): this
 
-  off<K extends keyof E>(t: K, callback: Callback<E[K]>): this
-
   emit<K extends keyof E>(t: K, value: E[K]): void
 }