title: ContextLoader.getCurrentWebApplicationContext() always returns null
body: <p>i'm running a web-app with <code>spring-boot</code> and have to use external articfacts which are using <code>ContextLoader.getCurrentWebApplicationContext()</code> to get some beans from.
  But it always returns <code>null</code>.
  According to the <code>spring-boot</code>documentation the parent application context is not a <code>WebApplicationContext</code>. Is there any other way to access the <code>WebApplicationContext</code> via <code>ContextLoader.getCurrentWebApplicationContext()</code>?</p>
  
  <p>Thanks in advance!</p>