Add test snapshot for displayName bug

Author: TrevorBurnham

src/__tests__/__fixtures__/DisplayName.tsx

@@ -0,0 +1,11 @@
+import * as React from "react";
+
+interface ButtonComponentProps {
+  text: string;
+}
+
+export const Button = (props: ButtonComponentProps) => (
+  <button>{props.text}</button>
+);
+
+Button.displayName = "MyButtonDisplayName";

src/__tests__/__snapshots__/generateDocgenCodeBlock.test.ts.snap

@@ -76,6 +76,28 @@ try {
 catch (__react_docgen_typescript_loader_error) { }"
 `;
 
+exports[`component fixture DisplayName.tsx has code block generated 1`] = `
+"import * as React from \\"react\\";
+
+interface ButtonComponentProps {
+  text: string;
+}
+
+export const Button = (props: ButtonComponentProps) => (
+  <button>{props.text}</button>
+);
+
+Button.displayName = \\"MyButtonDisplayName\\";
+
+try {
+    // @ts-ignore
+    MyButtonDisplayName.displayName = \\"MyButtonDisplayName\\";
+    // @ts-ignore
+    MyButtonDisplayName.__docgenInfo = { \\"description\\": \\"\\", \\"displayName\\": \\"MyButtonDisplayName\\", \\"props\\": { \\"text\\": { \\"defaultValue\\": null, \\"description\\": \\"\\", \\"name\\": \\"text\\", \\"required\\": true, \\"type\\": { \\"name\\": \\"string\\" } } } };
+}
+catch (__react_docgen_typescript_loader_error) { }"
+`;
+
 exports[`component fixture HyphenatedPropName.tsx has code block generated 1`] = `
 "import * as React from \\"react\\";