Add name-tests-test hook

diff --git a/manifest.yaml b/manifest.yaml
index 9202184..78fc797 100644
--- a/manifest.yaml
+++ b/manifest.yaml

@@ -17,3 +17,9 @@
     description: This hook trims trailing whitespace.
     entry: trailing-whitespace-fixer
     language: python
+-
+    id: name-tests-test
+    name: Tests should end in _test.py
+    description: This verifies that test files are named correctly
+    entry: name-tests-test
+    language: python
\ No newline at end of file

diff --git a/pre_commit_hooks/tests_should_end_in_test.py b/pre_commit_hooks/tests_should_end_in_test.py
new file mode 100644
index 0000000..86991f0
--- /dev/null
+++ b/pre_commit_hooks/tests_should_end_in_test.py

@@ -0,0 +1,24 @@
+
+import sys
+
+
+def validate_files(argv):
+    retcode = 0
+    for filename in argv:
+        if (
+            not filename.endswith('_test.py') and
+            not filename.endswith('__init__.py') and
+            not filename.endswith('/conftest.py')
+        ):
+            retcode = 1
+            print '{0} does not end in _test.py'.format(filename)
+
+    return retcode
+
+
+def entry():
+    validate_files(sys.argv[1:])
+
+
+if __name__ == '__main__':
+    sys.exit(entry())
\ No newline at end of file

diff --git a/setup.py b/setup.py
index 715f0c9..ed41748 100644
--- a/setup.py
+++ b/setup.py

@@ -15,6 +15,7 @@
         'console_scripts': [
             'debug-statement-hook = pre_commit_hooks.debug_statement_hook:entry',
             'trailing-whitespace-fixer = pre_commit_hooks.trailing_whitespace_fixer:entry',
+            'name-tests-test = pre_commit_hooks.tests_should_end_in_test:entry',
         ],
     },
 )