title: TypeORM's migration:generate regenerates the whole database schema
body: <p>Every time I run <code>migration:generate</code>, it creates a migration that regenerates the entire database schema (rather than a migration for just the recent changes to my entities). I'm using Typeorm version 0.2.7, the latest version.</p>
  
  <p>My <code>ormconfig.json</code> is:</p>
  
  <pre><code>{
    "host": "localhost",
    "logging": false,
    "port": 5432,
    "synchronize": false,
    "type": "postgres",
  
    "entities": ["build/server/entity/*.js"],
    "migrations": ["build/server/migration/*.js"],
  
    "cli": {
      "entitiesDir": "build/server/entity",
      "migrationsDir": "build/server/migration"
    },
  
    "username": "***",
    "password": "***",
    "database": "***"
  }
  </code></pre>
  
  <p>When I run <code>typeorm migration:generate -n SomeEntityChanges</code>, the new migration file contains instructions for creating and linking up tables for <em>all</em> my entities, even though most of them already have corresponding migrations in <code>build/server/migration</code>.</p>
  
  <p>When I run <code>typeorm migration:run</code>, I can see that there are no pending migrations, and that the migrations that cover the existing entities have been run (i.e. they're in my <code>migrations</code> table).</p>
  
  <p>What am I missing? The <a href="https://github.com/typeorm/typeorm/blob/master/docs/migrations.md#generating-migrations" rel="noreferrer">docs</a> say that the <code>migration:generate</code> command should just generate a migration with the recent changes.</p>