title: SQLite does not create an index
body: <p>I am working on some database migrations in Laravel 5.4. The migrations work fine with a MySQL database, but for testing I want to use SQLite but the migration fails. Here's the code</p>
  
  <pre><code>public function up()
      {
          Schema::create('mapped_venues', function (Blueprint $table) {
              $table-&gt;increments('id');
              $table-&gt;unsignedInteger('upload_job_id')-&gt;nullable();
              $table-&gt;string('venue')-&gt;default('');
              $table-&gt;unsignedInteger('venue_id')-&gt;nullable();
  
              $table-&gt;timestamps();
  
              $table-&gt;index(['venue']);
          });
  
          Schema::create('mapped_teams', function (Blueprint $table) {
              $table-&gt;increments('id');
              $table-&gt;unsignedInteger('upload_job_id')-&gt;nullable();
              $table-&gt;string('team')-&gt;default('');
              $table-&gt;unsignedInteger('team_id')-&gt;nullable();
  
              $table-&gt;timestamps();
  
              $table-&gt;index(['team']);
          });
      }
  </code></pre>
  
  <p>When I run <code>php artisan migrate</code> the index on the <code>mapped_teams.team</code> column is not created, but the one on <code>mapped_venues.venue</code> is!!</p>
  
  <pre><code>$ sqlite3 database/database.sqlite 
  SQLite version 3.19.3 2017-06-08 14:26:16
  Enter ".help" for usage hints.
  sqlite&gt; .indexes mapped_teams
  sqlite&gt; .indexes mapped_venues
  mapped_venues_venue_index
  sqlite&gt;
  </code></pre>
  
  <p>I have also tried to create the indexes on a separate call</p>
  
  <pre><code>Schema::table('mapped_venues', function (Blueprint $table) {
              $table-&gt;index(['venue']);
          });
  Schema::table('mapped_teams', function (Blueprint $table) {
              $table-&gt;index(['team']);
          });
  </code></pre>
  
  <p>But the result is the same. Interestingly though, when (by mistake) I left the creation of the index <code>$table-&gt;index['team'])</code> inside the call to create the table (so, I have two calls to create the index) I get the error that the index <code>mapped_teams_team_index</code> already exists.</p>
  
  <p>I am using:</p>
  
  <ul>
  <li>Laravel 5.4.36</li>
  <li>Doctrine DBal 2.6.2</li>
  <li>SQLite 3.19.3</li>
  </ul>