prettier 2

Summary:
Quick notes:

- This looks worse than it is. It adds mandatory parentheses to single argument lambdas. Lots of outrage on Twitter about it, personally I'm {emoji:1f937_200d_2642} about it.
- Space before function, e.g. `a = function ()` is now enforced. I like this because both were fine before.
- I added `eslint-config-prettier` to the config because otherwise a ton of rules conflict with eslint itself.

Close https://github.com/facebook/flipper/pull/915

Reviewed By: jknoxville

Differential Revision: D20594929

fbshipit-source-id: ca1c65376b90e009550dd6d1f4e0831d32cbff03

desktop/plugins/sandbox/index.tsx

@@ -104,7 +104,7 @@ export default class SandboxView extends FlipperPlugin<
               placeholder="Sandbox URL (e.g. unixname.sb.facebook.com)"
               key="sandbox-url"
               onChange={this.onChangeSandbox}
-              onKeyPress={event => {
+              onKeyPress={(event) => {
                 if (event.key === 'Enter') {
                   this.onSendSandboxEnvironment(this.state.customSandbox);
                 }
@@ -124,7 +124,7 @@ export default class SandboxView extends FlipperPlugin<
             Success!
           </SandboxView.FeedbackMessage>
         </SandboxView.TextInputLayout>
-        {this.state.sandboxes.map(sandbox => (
+        {this.state.sandboxes.map((sandbox) => (
           <ButtonContainer>
             <BigButton
               key={sandbox.value}