Change exception message checking to match pytest 5.

From [the pytest changelog](https://docs.pytest.org/en/latest/changelog.html#pytest-5-0-0-2019-06-28):

> ExceptionInfo objects (returned by pytest.raises) now have the same str representation as repr, which avoids some confusion when users use print(e) to inspect the object.

normandy/base/tests/api/test_api.py

@@ -140,7 +140,7 @@ def test_register_view_requires_name(self):
         router = MixedViewRouter()
         with pytest.raises(TypeError) as err:
             router.register_view("view", View, allow_cdn=True)
-        assert "missing 1 required keyword-only argument: 'name'" in str(err)
+        assert "missing 1 required keyword-only argument: 'name'" in str(err.value)
 
     def test_get_urls_includes_non_viewset_views(self):
         router = MixedViewRouter()

normandy/recipes/tests/test_exports.py

@@ -48,21 +48,21 @@ def test_it_checks_config(self, settings):
         settings.REMOTE_SETTINGS_PASSWORD = "p4ssw0rd"
         with pytest.raises(ImproperlyConfigured) as exc:
             exports.RemoteSettings().check_config()
-        assert "REMOTE_SETTINGS_USERNAME" in str(exc)
+        assert "REMOTE_SETTINGS_USERNAME" in str(exc.value)
 
         # Set empty USERNAME
         settings.REMOTE_SETTINGS_USERNAME = ""
         with pytest.raises(ImproperlyConfigured) as exc:
             exports.RemoteSettings().check_config()
-        assert "REMOTE_SETTINGS_USERNAME" in str(exc)
+        assert "REMOTE_SETTINGS_USERNAME" in str(exc.value)
 
         # Leave out PASSWORD
         settings.REMOTE_SETTINGS_URL = "http://some-server/v1"
         settings.REMOTE_SETTINGS_USERNAME = "usename"
         settings.REMOTE_SETTINGS_PASSWORD = None
         with pytest.raises(ImproperlyConfigured) as exc:
             exports.RemoteSettings().check_config()
-        assert "REMOTE_SETTINGS_PASSWORD" in str(exc)
+        assert "REMOTE_SETTINGS_PASSWORD" in str(exc.value)
 
         # Leave out COLLECTION_ID
         settings.REMOTE_SETTINGS_URL = "http://some-server/v1"
@@ -71,7 +71,7 @@ def test_it_checks_config(self, settings):
         settings.REMOTE_SETTINGS_COLLECTION_ID = None
         with pytest.raises(ImproperlyConfigured) as exc:
             exports.RemoteSettings().check_config()
-        assert "REMOTE_SETTINGS_COLLECTION_ID" in str(exc)
+        assert "REMOTE_SETTINGS_COLLECTION_ID" in str(exc.value)
 
     def test_check_connection(self, rs_settings, requestsmock):
         # Root URL should return currently authenticated user.
@@ -80,7 +80,7 @@ def test_check_connection(self, rs_settings, requestsmock):
 
         with pytest.raises(ImproperlyConfigured) as exc:
             exports.RemoteSettings().check_config()
-        assert "Invalid Remote Settings credentials" in str(exc)
+        assert "Invalid Remote Settings credentials" in str(exc.value)
 
         requestsmock.get(
             f"{rs_settings.REMOTE_SETTINGS_URL}/",
@@ -112,7 +112,7 @@ def test_check_connection(self, rs_settings, requestsmock):
         assert (
             f"Remote Settings collection {rs_settings.REMOTE_SETTINGS_COLLECTION_ID} "
             "is not writable"
-        ) in str(exc)
+        ) in str(exc.value)
 
         requestsmock.get(
             collection_url,
@@ -128,7 +128,7 @@ def test_check_connection(self, rs_settings, requestsmock):
         assert (
             "Review was not disabled on Remote Settings collection "
             f"{rs_settings.REMOTE_SETTINGS_COLLECTION_ID}."
-        ) in str(exc)
+        ) in str(exc.value)
 
         requestsmock.get(
             f"{rs_settings.REMOTE_SETTINGS_URL}/",

normandy/recipes/tests/test_signing.py

@@ -34,23 +34,23 @@ def test_it_checks_settings(self, settings):
         settings.AUTOGRAPH_HAWK_SECRET_KEY = "hawk secret key"
         with pytest.raises(ImproperlyConfigured) as exc:
             signing.Autographer()
-        assert "AUTOGRAPH_URL" in str(exc)
+        assert "AUTOGRAPH_URL" in str(exc.value)
 
         # Leave out HAWK_ID
         settings.AUTOGRAPH_URL = "https://autograph.example.com"
         settings.AUTOGRAPH_HAWK_ID = None
         settings.AUTOGRAPH_HAWK_SECRET_KEY = "hawk secret key"
         with pytest.raises(ImproperlyConfigured) as exc:
             signing.Autographer()
-        assert "AUTOGRAPH_HAWK_ID" in str(exc)
+        assert "AUTOGRAPH_HAWK_ID" in str(exc.value)
 
         # Leave out HAWK_SECRET_KEY
         settings.AUTOGRAPH_URL = "https://autograph.example.com"
         settings.AUTOGRAPH_HAWK_ID = "hawk id"
         settings.AUTOGRAPH_HAWK_SECRET_KEY = None
         with pytest.raises(ImproperlyConfigured) as exc:
             signing.Autographer()
-        assert "AUTOGRAPH_HAWK_SECRET_KEY" in str(exc)
+        assert "AUTOGRAPH_HAWK_SECRET_KEY" in str(exc.value)
 
         # Include everything
         settings.AUTOGRAPH_URL = "https://autograph.example.com"
@@ -171,13 +171,13 @@ def test_incomplete_cert(self):
         bad_data = "-----BEGIN CERTIFICATE-----\nMIIGXTCCBEWgAwIBAgIEAQAACjANBgkq"
         with pytest.raises(signing.CertificateParseError) as exc:
             signing.extract_certs_from_pem(bad_data)
-        assert "Unexpected end of input." in str(exc)
+        assert "Unexpected end of input." in str(exc.value)
 
     def test_not_a_cert(self):
         bad_data = "hello world"
         with pytest.raises(signing.CertificateParseError) as exc:
             signing.extract_certs_from_pem(bad_data)
-        assert 'Unexpected input "hello world"' in str(exc)
+        assert 'Unexpected input "hello world"' in str(exc.value)
 
 
 class TestParseCertsFromDer(object):
@@ -391,5 +391,5 @@ def test_it_reads_general_time_format(self):
     def test_it_errors_on_unsupported_formats(self):
         with pytest.raises(signing.BadCertificate) as exc:
             signing.read_timestamp_object({"unsupportedTimestamp": b"gibberish"})
-        assert "Timestamp not in expected format" in str(exc)
-        assert "unsupportedTimestamp" in str(exc)
+        assert "Timestamp not in expected format" in str(exc.value)
+        assert "unsupportedTimestamp" in str(exc.value)

normandy/recipes/tests/test_utils.py

@@ -35,9 +35,9 @@ def test_error_cases(self, bad_val):
             fraction_to_key(bad_val)
 
         # Check that it is the expected error, not some spurious error from elsewhere.
-        assert "must be between 0 and 1 inclusive" in str(exc)
+        assert "must be between 0 and 1 inclusive" in str(exc.value)
         # Check that the bad value is mentioned
-        assert str(bad_val) in str(exc)
+        assert str(bad_val) in str(exc.value)
 
     def test_result_length(self):
         for _ in range(100):