Add functional test for citations pages

The problem in LMFDB#2332 went unnoticed because of a lack of testing. This
commit adds tests for the base citations page and the "How to Cite" the
lmfdb page. These tests really just check that these pages exist. It
also tests a specific reference in the citation list and tests for its
bib entry in the associated bibliography list. This would catch the
problem from LMFDB#2332.

Note that I've also submitted a pull request to the LMFDB/citations
repository to prevent this issue from coming up. This is
LMFDB/citations#9

Author: davidlowryduda

lmfdb/test_citations.py

@@ -0,0 +1,39 @@
+# -*- coding: utf-8 -*-
+from lmfdb.base import LmfdbTest
+
+
+class CitationTest(LmfdbTest):
+    '''
+    Test that the citations page exists and the associated bib page exists
+    '''
+
+    def test_citation_root(self):
+        '''
+        Checking /citation page
+        '''
+        r = self.tc.get('/citation')
+        assert "A list of articles which cite the LMFDB" in r.data
+
+    def test_how_to_cite(self):
+        '''
+        Checking "How to Cite" /citation/citing
+        '''
+        r = self.tc.get('/citation/citing')
+        assert "The BibTeX entry is" in r.data
+        assert "To cite a specific page in the LMFDB" in r.data
+
+    def test_citation_specific(self):
+        '''
+        Checking that a known citation appears in /citation/citations list
+        '''
+        r = self.tc.get('/citation/citations')
+        assert "Thomas A Hulse" in r.data
+        assert "Counting square discriminants" in r.data
+
+    def test_cite_bib(self):
+        '''
+        Checking that a known bib is in /citation/citations_bib bibliography
+        '''
+        r = self.tc.get('/citation/citations_bib')
+        assert "Hulse, Thomas A" in r.data
+        assert "Counting square discriminants" in r.data