Tests: Add tests for current and future GMP versions

Add tests to make sure the detected protocol version and instance is
correct for GMP 22.7.

Also add tests for the expected next protocol version (`22.8`) and a
possible far future version (`22.20`), which should adequately fall back
to the latest current version.

Author: wiegandm

tests/protocols/gmp/test_context_manager.py

@@ -11,6 +11,7 @@
 from gvm.protocols.gmp._gmp224 import GMPv224
 from gvm.protocols.gmp._gmp225 import GMPv225
 from gvm.protocols.gmp._gmp226 import GMPv226
+from gvm.protocols.gmp._gmp227 import GMPv227
 from tests.protocols import GmpTestCase
 
 
@@ -133,6 +134,49 @@ def test_select_gmpv226(self):
             self.assertEqual(gmp.get_protocol_version(), (22, 6))
             self.assertIsInstance(gmp, GMPv226)
 
+    def test_select_gmpv227(self):
+        self.connection.read.return_value(
+            b'<get_version_response status="200" status_text="OK">'
+            b"<version>22.07</version>"
+            b"</get_version_response>"
+        )
+
+        with self.gmp as gmp:
+            self.assertEqual(gmp.get_protocol_version(), (22, 7))
+            self.assertIsInstance(gmp, GMPv227)
+
+        self.connection.read.return_value(
+            b'<get_version_response status="200" status_text="OK">'
+            b"<version>22.7</version>"
+            b"</get_version_response>"
+        )
+
+        with self.gmp as gmp:
+            self.assertEqual(gmp.get_protocol_version(), (22, 7))
+            self.assertIsInstance(gmp, GMPv227)
+
+    def test_next_version_fallback(self):
+        self.connection.read.return_value(
+            b'<get_version_response status="200" status_text="OK">'
+            b"<version>22.8</version>"
+            b"</get_version_response>"
+        )
+
+        with self.gmp as gmp:
+            self.assertEqual(gmp.get_protocol_version(), (22, 7))
+            self.assertIsInstance(gmp, GMPv227)
+
+    def test_newer_version_fallback(self):
+        self.connection.read.return_value(
+            b'<get_version_response status="200" status_text="OK">'
+            b"<version>22.20</version>"
+            b"</get_version_response>"
+        )
+
+        with self.gmp as gmp:
+            self.assertEqual(gmp.get_protocol_version(), (22, 7))
+            self.assertIsInstance(gmp, GMPv227)
+
     def test_unknown_protocol(self):
         self.connection.read.return_value(
             b'<get_version_response status="200" status_text="OK">'