Fix context for beforeEach and afterEach hooks in Flow type definition file (#1344)

Author: zs-zs

index.js.flow

@@ -187,8 +187,8 @@ declare module.exports: {
 	(              run: ContextualTest): void;
 	(name: string, run: ContextualTest): void;
 
-	beforeEach : TestMethod;
-	afterEach  : TestMethod;
+	beforeEach : ContextualTestMethod;
+	afterEach  : ContextualTestMethod;
 	serial     : ContextualTestMethod;
 	before     : ContextualTestMethod;
 	after      : ContextualTestMethod;

test/flow-types/regression-1114.js.flow

@@ -26,7 +26,6 @@ test.cb(t => {
 });
 
 test.beforeEach(t => {
-	// $ExpectError: Unknown property "context"
 	const context = t.context;
 })