PYTHON-1643 Resync read write concern spec tests

test/read_write_concern/connection-string/read-concern.json

@@ -24,6 +24,24 @@
       "readConcern": {
         "level": "majority"
       }
+    },
+    {
+      "description": "linearizable specified",
+      "uri": "mongodb://localhost/?readConcernLevel=linearizable",
+      "valid": true,
+      "warning": false,
+      "readConcern": {
+        "level": "linearizable"
+      }
+    },
+    {
+      "description": "available specified",
+      "uri": "mongodb://localhost/?readConcernLevel=available",
+      "valid": true,
+      "warning": false,
+      "readConcern": {
+        "level": "available"
+      }
     }
   ]
 }

test/read_write_concern/document/read-concern.json

@@ -28,6 +28,39 @@
         "level": "local"
       },
       "isServerDefault": false
+    },
+    {
+      "description": "Linearizable",
+      "valid": true,
+      "readConcern": {
+        "level": "linearizable"
+      },
+      "readConcernDocument": {
+        "level": "linearizable"
+      },
+      "isServerDefault": false
+    },
+    {
+      "description": "Snapshot",
+      "valid": true,
+      "readConcern": {
+        "level": "snapshot"
+      },
+      "readConcernDocument": {
+        "level": "snapshot"
+      },
+      "isServerDefault": false
+    },
+    {
+      "description": "Available",
+      "valid": true,
+      "readConcern": {
+        "level": "available"
+      },
+      "readConcernDocument": {
+        "level": "available"
+      },
+      "isServerDefault": false
     }
   ]
 }