Revert "Add databaseId for encoding and decoding keys"

This reverts commit 0ebabd5.

Author: danieljbruce

src/entity.ts

@@ -282,7 +282,6 @@ export namespace entity {
  }
 
  export interface KeyOptions {
- databaseId?: string;
  namespace?: string;
  path: PathType[];
  }
@@ -365,7 +364,6 @@ export namespace entity {
  */
  export class Key {
  namespace?: string;
- databaseId?: string;
  id?: string;
  name?: string;
  kind: string;
@@ -378,7 +376,6 @@ export namespace entity {
  * @type {string}
  */
  this.namespace = options.namespace;
- this.databaseId = options.databaseId;
 
  options.path = [].slice.call(options.path);
 
@@ -1115,20 +1112,10 @@ export namespace entity {
  path: [],
  };
 
- if (key.namespace || key.databaseId) {
- keyProto.partitionId = Object.assign(
- {},
- key.namespace
- ? {
- namespaceId: key.namespace,
- }
- : null,
- key.databaseId
- ? {
- databaseId: key.databaseId,
- }
- : null
- );
+ if (key.namespace) {
+ keyProto.partitionId = {
+ namespaceId: key.namespace,
+ };
  }
 
  let numKeysWalked = 0;