feat(test): add mock modules for fetch() and console

ui/src/__mocks__/Console.js

@@ -0,0 +1,4 @@
+const ConsoleMock = level =>
+  jest.spyOn(console, level).mockImplementation(() => jest.fn());
+
+export { ConsoleMock };

ui/src/__mocks__/Fetch.js

@@ -0,0 +1,41 @@
+import moment from "moment";
+
+const FetchMock = data =>
+  jest.fn().mockImplementation(() =>
+    Promise.resolve({
+      json: () => data
+    })
+  );
+
+const EmptyAPIResponse = () => ({
+  status: "success",
+  timestamp: moment().toISOString(),
+  version: "fakeVersion",
+  upstreams: {
+    counters: { total: 1, healthy: 1, failed: 0 },
+    instances: [{ name: "default", uri: "file:///mock", error: "" }]
+  },
+  silences: { default: {} },
+  groups: {},
+  totalAlerts: 0,
+  colors: {},
+  filters: [
+    {
+      text: "label=value",
+      name: "label",
+      matcher: "=",
+      value: "value",
+      hits: 0,
+      isValid: true
+    }
+  ],
+  counters: {},
+  settings: {
+    staticColorLabels: ["job"],
+    annotationsDefaultHidden: false,
+    annotationsHidden: [],
+    annotationsVisible: []
+  }
+});
+
+export { FetchMock, EmptyAPIResponse };