[cache] Change according to 1.4.x branch

Test was failling previously

beat/cmdline/cache.py

@@ -78,13 +78,7 @@ def clear(ctx):
     if os.path.isdir(ctx.meta['config'].cache):
         for k in os.listdir(ctx.meta['config'].cache):
             p = os.path.join(ctx.meta['config'].cache, k)
-            if os.path.isfile(p):
-                shutil.rmtree(p)
-            else:
-                raise click.ClickException("Failed to clear cache %s." % p)
-    else:
-        raise click.ClickException("Cache directory does not exist: %s" %
-                                   ctx.meta['config'].cache)
+            shutil.rmtree(p)
 
 
 @cache.command()