Feat: Logout feature ios, android and web

[sallyg1]

is Logout feature ready to be use ? I see this in the definitions file

/**
 * @since 3.1.0 ... not implemented yet!
 */
logoutUrl?: string;

onLogoutClick() {
OAuth2Client.logout(
oauth2LogoutOptions
).then(() => {
// do something
}).catch(reason => {
console.error("OAuth logout failed", reason);
});
}

Where how do we specify oauth2LogoutOptions ?

[meriturva]

I can confirm that logout is not working as expected. Just clear local storage and nothing more.

[meriturva]

See: #97