adds accessible close button to Alert (#386)

Author: jasonbasuil

spec/__snapshots__/Storyshots.test.js.snap

@@ -290,6 +290,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
+        aria-label="close"
         className="close"
         onClick={[Function]}
         type="button"
@@ -363,6 +364,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
+        aria-label="close"
         className="close"
         onClick={[Function]}
         type="button"
@@ -436,6 +438,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
+        aria-label="close"
         className="close"
         onClick={[Function]}
         type="button"
@@ -509,6 +512,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
+        aria-label="close"
         className="close"
         onClick={[Function]}
         type="button"
@@ -582,6 +586,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
+        aria-label="close"
         className="close"
         onClick={[Function]}
         type="button"
@@ -694,6 +699,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
+        aria-label="close"
         className="close"
         onClick={[Function]}
         type="button"
@@ -809,6 +815,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
+        aria-label="close"
         className="close"
         onClick={[Function]}
         type="button"
@@ -882,6 +889,7 @@ exports[`Storyshots Design System/Alert With Dismiss 1`] = `
       className="Alert__close"
     >
       <button
+        aria-label="close"
         className="close"
         onClick={[Function]}
         type="button"

src/Alert/Alert.jsx

@@ -96,6 +96,7 @@ function Alert(props) {
         props.onDismiss && (
           <div className="Alert__close">
             <button
+              aria-label="close"
               className="close"
               type="button"
               onClick={() => props.onDismiss(props.id)}

src/Toast/__snapshots__/withToast.test.jsx.snap

@@ -35,6 +35,7 @@ Array [
       className="Alert__close"
     >
       <button
+        aria-label="close"
         className="close"
         onClick={[Function]}
         type="button"