fix: hide default orange outline around gitify logo on first start (gitify-app#917)

Author: setchy

src/components/Sidebar.tsx

@@ -46,7 +46,7 @@ export const Sidebar: React.FC = () => {
     <div className="flex flex-col fixed left-14 w-14 -ml-14 h-full bg-gray-sidebar overflow-y-auto	">
       <div className="flex flex-col flex-1 items-center py-4">
         <button
-          className="w-5 my-3 mx-auto cursor-pointer"
+          className="w-5 my-3 mx-auto cursor-pointer outline-none"
           title="Open Gitify on GitHub"
           onClick={onOpenBrowser}
           data-testid="gitify-logo"

src/components/__snapshots__/Sidebar.test.tsx.snap

@@ -8,7 +8,7 @@ exports[`components/Sidebar.tsx should render itself & its children (logged in)
     className="flex flex-col flex-1 items-center py-4"
   >
     <button
-      className="w-5 my-3 mx-auto cursor-pointer"
+      className="w-5 my-3 mx-auto cursor-pointer outline-none"
       data-testid="gitify-logo"
       onClick={[Function]}
       title="Open Gitify on GitHub"
@@ -133,7 +133,7 @@ exports[`components/Sidebar.tsx should render itself & its children (logged out)
     className="flex flex-col flex-1 items-center py-4"
   >
     <button
-      className="w-5 my-3 mx-auto cursor-pointer"
+      className="w-5 my-3 mx-auto cursor-pointer outline-none"
       data-testid="gitify-logo"
       onClick={[Function]}
       title="Open Gitify on GitHub"