Moving Jest setup and consolidating

src/setup/jest.js

@@ -0,0 +1,16 @@
+import Enzyme from 'enzyme';
+import Adapter from 'enzyme-adapter-react-16';
+
+Enzyme.configure({ adapter: new Adapter() });
+
+const env = { ...process.env };
+
+beforeEach(() => {
+  process.env = {
+    ...process.env
+  };
+});
+
+afterEach(() => {
+  process.env = env;
+});