#250: Add test class for ICATClient

- Class used to create object pools of Python ICAT's client class

test/icat/test_icat_client.py

@@ -0,0 +1,17 @@
+from icat.client import Client
+
+from datagateway_api.common.icat.icat_client_pool import ICATClient
+
+
+class TestICATClient:
+    def test_init(self):
+        test_icat_client = ICATClient()
+        assert isinstance(test_icat_client, Client)
+
+        assert not test_icat_client.autoLogout
+
+    def test_clean_up(self):
+        test_icat_client = ICATClient()
+        assert id(test_icat_client) in Client.Register
+        test_icat_client.clean_up()
+        assert id(test_icat_client) not in Client.Register