feat: remove 'legacy' parameter

BREAKING CHANGE: The legacy protocol support was removed from Cloud SDK 267.0.0

index.d.ts

@@ -48,13 +48,6 @@ interface Options {
    */
   debug?: boolean;
 
-  /**
-   * Default: false
-   *
-   * If it is true, it supports Cloud Datastore API v1beta2.
-   */
-  legacy?: boolean;
-
   /**
    * Default: '1.0'
    *

readme.md

@@ -36,7 +36,6 @@ describe('test suit', ()=>{
 
     before(()=>{
         const options = {
-            legacy: true, // if you need legacy support
             useDocker: true // if you need docker image
         };
 
@@ -67,7 +66,6 @@ clean (boolean) | true | If dataDir value is set and 'clean' value is true then
 host (string) | localhost | If it is empty the'localhost' of google default value is used. It can take the form of a single address (hostname, IPv4, or IPv6)
 port (number) | 8081 | If it is empty the emulator selects a random free port. If use docker version always set port.
 debug (boolean) | false | If it is true, it writes the console.logs of the emulator onto the main process console.
-legacy (boolean) | false | If it is true, it supports Cloud Datastore API v1beta2.
 consistency (string) | '1.0' | The consistency level of the Datastore Emulator. [More details](https://cloud.google.com/sdk/gcloud/reference/beta/emulators/datastore/start) 
 useDocker (boolean) | false | If it is true, it use docker image to run emulator instead of locally installed version.
 dockerImage (string) | 'google/cloud-sdk:latest' | This image will be use by docker. The default: [google/cloud-sdk:latest](https://hub.docker.com/r/google/cloud-sdk/)

src/base-emulator.js

@@ -165,11 +165,6 @@ class BaseEmulator {
       params.push('--no-store-on-disk')
     }
 
-    if (this._options.legacy) {
-      console.warn('"legacy" parameter is deprecated by Google. It will be removed in early October 2019')
-      params.push('--legacy')
-    }
-
     this._setConsistency(params);
 
     return params;

src/datastore-emulator.js

@@ -2,7 +2,6 @@
 
 const DEFAULT_OPTIONS = {
   storeOnDisk: false,
-  legacy: false,
   clean: true,
   debug: false,
   useDocker: false,