Columns with the type "enum" are not supported in the migration API

Issue type:

[ ] question [x] bug report [ ] feature request [ ] documentation issue

Database system/driver:

[ ] cordova [ ] mongodb [ ] mssql [ ] mysql / mariadb [ ] oracle [x] postgres [ ] cockroachdb [ ] sqlite [ ] sqljs [ ] react-native [ ] expo

TypeORM version:

[x] latest [ ] @next [ ] 0.x.x (or put your version here)

Steps to reproduce or a small repository showing the problem:

When writing migrations by hand using the migration API to create a new table that has an enum column 3 things happen that shouldn’t:

• The generated SQL does not sets the column’s type to enum.
• Worse, it sets the column’s type to “[Tablename]_[column]_enum”.
• The “enum” TableColumnOptions parameter gets ignored.

A simple example:

// == The entity

export enum RatingType {
  low = 'bad',
  neutral = 'neutral',
  good = 'good'
}

@Entity({ name: 'Ratings' })
export default class Rating extends BaseEntity {
  @PrimaryGeneratedColumn('uuid')
  id: string

  @Column({ type: 'enum', enum: RatingType })
  rating: RatingType
}

// == The migration

import { MigrationInterface, QueryRunner, Table } from 'typeorm'

export class CreateRatings1569818629816 implements MigrationInterface {
  private ratingsTable = new Table({
    name: 'Ratings',
    columns: [
      {
        name: 'id',
        type: 'uuid',
        isPrimary: true,
        isGenerated: true,
        generationStrategy: 'uuid',
      },
      {
        name: 'rating',
        type: 'enum',
        enum: ['bad', 'neutral', 'good'],
        isNullable: true
      }
    ],
  })

  async up(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.createTable(this.ratingsTable, true)
  }

  async down(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.dropTable(this.ratingsTable)
  }
}

The generated SQL looks like this:

CREATE TABLE "Ratings" (
  "id" uuid NOT NULL DEFAULT uuid_generate_v4(),
  "rating" "Ratings_rating_enum",
  CONSTRAINT "PK_ee6436ff188c9bb00cc70fc447a" PRIMARY KEY ("id")
)