title: Run Liquibase changesets by context name
body: <p><em>Is there any way to run only group of changesets with Liquibase API?</em></p>
  
  <p>The following code initialize the whole schema before starting integration test class:</p>
  
  <pre><code>liquibase = new Liquibase(
      LIQUIBASE_CHANGELOG_PATH,
      new FileSystemResourceAccessor(),
      new JdbcConnection(embeddedTestDatabase.getConnection())
  );
  liquibase.dropAll();
  liquibase.update(""); // PROBLEM: for some reason this launch all changesets including changesets with name `test`
  </code></pre>
  
  <p>Now I want to do something like DBUnit's <code>@DatabaseSetup</code> before specific test method - means execute only changesets with <code>test</code> context:</p>
  
  <pre><code>liquibase.update("test"); // PROBLEM : this also run all changesets
  
  &lt;changeSet author="me" id="some_id" logicalFilePath="some_path" context="test"&gt;
      &lt;sql&gt;
          INSERT INTO COMPANY (ID, CREATED_AT, CREATED_BY, NAME) VALUES (1, '2017-09-15 16:55:57.558', 'My company');
      &lt;/sql&gt;
      &lt;rollback&gt;
          DELETE FROM COMPANY;
      &lt;/rollback&gt;
  &lt;/changeSet&gt;
  </code></pre>