Added navigation to application, internationalization, and sign in screen.

components/sign-out-button/sign-out-button.component.jsx

@@ -0,0 +1,24 @@
+import React from "react";
+import { useTranslation } from "react-i18next";
+import { Button } from "react-native";
+import { connect } from "react-redux";
+import { createStructuredSelector } from "reselect";
+import { signOutStart } from "../../redux/user/user.actions";
+const mapStateToProps = createStructuredSelector({
+  //currentUser: selectCurrentUser
+});
+const mapDispatchToProps = (dispatch) => ({
+  //setUserLanguage: language => dispatch(setUserLanguage(language))
+  signOutStart: () => dispatch(signOutStart()),
+});
+
+export function SignOutButton({ signOutStart }) {
+  const { t } = useTranslation();
+  return (
+    <Button
+      onPress={() => signOutStart()}
+      title={t("general.actions.signout")}
+    />
+  );
+}
+export default connect(mapStateToProps, mapDispatchToProps)(SignOutButton);