do a requirements bump

notable changes:

* Flask 1.1 treats redirects to itself as relative URLs now, so a spate
  of tests were updated

tests/functional_tests.py

@@ -134,32 +134,32 @@ def test_that_page_request_redirects_to_directory(client):
     """
     response = client.get('/subdir')
     assert response.status_code == 301
-    assert response.location == 'http://localhost/subdir/'
+    assert response.location == '/subdir/'
 
 
 def test_that_request_to_symlink_redirects_markdown(client):
     """Test that a request to /foo redirects to /what-foo-points-at."""
     response = client.get('/symlink-to-no-title')
     assert response.status_code == 301
-    assert response.location == 'http://localhost/no-title'
+    assert response.location == '/no-title'
 
 
 def test_that_request_to_symlink_redirects_file(client):
     """Test that a request to /foo.txt redirects to /what-foo-points-at.txt."""
     response = client.get('/symlink-to-foo.txt')
     assert response.status_code == 301
-    assert response.location == 'http://localhost/foo.txt'
+    assert response.location == '/foo.txt'
 
 
 def test_that_request_to_symlink_redirects_directory(client):
     """Test that a request to /foo/ redirects to /what-foo-points-at/."""
     response = client.get('/symlink-to-subdir/')
     assert response.status_code == 301
-    assert response.location == 'http://localhost/subdir'
+    assert response.location == '/subdir'
     # sadly, this location also redirects
     response = client.get('/subdir')
     assert response.status_code == 301
-    assert response.location == 'http://localhost/subdir/'
+    assert response.location == '/subdir/'
     # but we do get there
     response = client.get('/subdir/')
     assert response.status_code == 200
@@ -169,7 +169,7 @@ def test_that_request_to_symlink_redirects_subdirectory(client):
     """Test that a request to /foo/bar redirects to /what-foo-points-at/bar."""
     response = client.get('/symlink-to-subdir/page-no-title')
     assert response.status_code == 301
-    assert response.location == 'http://localhost/subdir/page-no-title'
+    assert response.location == '/subdir/page-no-title'
     response = client.get('/subdir/page-no-title')
     assert response.status_code == 200