Remove rstlint because sphinx does it internally

Signed-off-by: Reece Dunham <me@rdil.rocks>

requirements-dev.txt

@@ -1,7 +1,6 @@
 setuptools==47.1.1
 wheel==0.34.2
 twine==3.1.1
-restructuredtext_lint==1.3.1
 unittest-xml-reporting==3.0.2
 sphinx==3.1.1
 sphinx-rtd-theme==0.4.3

tests.py

@@ -3,7 +3,6 @@
 # Import needed modules
 import unittest
 import os
-import restructuredtext_lint
 
 # Try to import area4.
 # This will fail if it could not be installed or if faulty code is present.
@@ -141,13 +140,6 @@ def test_info(self):
             ),
         )
 
-    def test_restructuredtext(self):
-        """Lint RST files."""
-        files = os.listdir("{0}/docs".format(self.working_directory))
-        for name in files:
-            path = "{0}/docs/{1}".format(self.working_directory, name)
-            restructuredtext_lint.lint_file(filepath=path)
-
     def test_make_div(self):
         """Test make_div."""
         self.assertEqual(