ADD: example of json api request for global discipline #473

tests/global_discipline_long.json

+{
+  "year": "2018",
+  "semester": "2",
+  "groups": [
+    {
+      "faculty": "000001387",
+      "subject": "Математика",
+      "externalID": "000000002",
+      "type": "Зачет",
+      "teachers": [
+        {
+          "id": "F6930CAE2DC449852775EDC953649339430BA297"
+        },
+        {
+          "id": "45D58A5A2C33C45D02FAAC3829E28A0E6DF19C0E"
+        }
+      ],
+
+      "students": [
+        {
+          "id": "ММ-14-0079"
+        },
+        {
+          "id": "ЮР-13-0118"
+        },
+        {
+          "id": "АИ-18-0129"
+        },
+        {
+          "id": "ПП-17-0140"
+        },
+        {
+          "id": "ЮУ-18-0324"
+        },
+        {
+          "id": "КТ-18-0205"
+        },
+        {
+          "id": "ИС-15-0017"
+        }
+      ]
+    }
+  ]
+}