Don't blacklist test_usetex using pytest

jenshnielsen · jenshnielsen · commit 8e4dd957e25e · 2016-08-31T09:09:27.000+01:00
The tests where fixed in #6918 but not enabled for pytest
diff --git a/conftest.py b/conftest.py
@@ -14,9 +14,7 @@
 
 
 IGNORED_TESTS = {
-    'matplotlib': [
-        'test_usetex',
-    ],
+    'matplotlib': [],
 }
 
 
