Fix failing tests from #5340 (#5342)

Author: seanpoulter

packages/jest-editor-support/src/__tests__/process.test.js

@@ -86,10 +86,7 @@ describe('createProcess', () => {
   });
 
   it('defines the "CI" environment variable', () => {
-    const expected = {
-      ...process.env,
-      CI: 'true',
-    };
+    const expected = Object.assign({}, process.env, {CI: 'true'});
 
     const workspace: any = {pathToJest: ''};
     const args = [];

packages/jest-editor-support/src/__tests__/runner.test.js

@@ -260,6 +260,7 @@ describe('events', () => {
     fakeProcess = (new EventEmitter(): any);
     fakeProcess.stdout = new EventEmitter();
     fakeProcess.stderr = new EventEmitter();
+    fakeProcess.kill = () => {};
 
     (createProcess: any).mockImplementation(() => fakeProcess);