Fix unit tests for glob updates.

The aforementioned change to `glob` surfaced a couple errors in the unit tests:

1. `test_glob_literal` was still testing the old behavior of non-existing paths
   being filtered out.
2. The post-process tests (`test_post_process_dry_run` and `test_post_process`)
   were now failing because post-process was being run without first collecting
   the media. This is a case where non-existing files were previously being
   filtered out silently but now cause an error. Running the collection stage
   before testing `post_process.

tests/tests/test_glob.py

@@ -55,7 +55,6 @@ class GlobTest(TestCase):
         self.assertSequenceEqual(self.glob('a'), [self.normpath('a')])
         self.assertSequenceEqual(self.glob('a', 'D'), [self.normpath('a', 'D')])
         self.assertSequenceEqual(self.glob('aab'), [self.normpath('aab')])
-        self.assertSequenceEqual(self.glob('zymurgy'), [])
 
     def test_glob_one_directory(self):
         self.assertSequenceEqual(

tests/tests/test_storage.py

@@ -6,6 +6,7 @@ from django.core.management import call_command
 from django.test import TestCase
 from django.test.utils import override_settings, modify_settings
 
+from pipeline.collector import default_collector
 from pipeline.storage import PipelineStorage
 
 from tests.tests.test_compiler import DummyCompiler
@@ -49,11 +50,13 @@ class StorageTest(TestCase):
 
     @pipeline_settings(JS_COMPRESSOR=None, CSS_COMPRESSOR=None)
     def test_post_process_dry_run(self):
+        default_collector.collect()
         processed_files = PipelineStorage().post_process({}, True)
         self.assertEqual(list(processed_files), [])
 
-    @pipeline_settings(JS_COMPRESSOR=None, CSS_COMPRESSOR=None)
+    @pipeline_settings(JS_COMPRESSOR=None, CSS_COMPRESSOR=None, COMPILERS=['tests.tests.test_storage.DummyCSSCompiler'])
     def test_post_process(self):
+        default_collector.collect()
         storage = PipelineStorage()
         processed_files = storage.post_process({})
         self.assertTrue(('screen.css', 'screen.css', True) in processed_files)