Check for required scopes and update readme

[thomaswelton]

Some providers require you to pass in at least one scope field, unlike Facebook for example that will default to the "basic" scope if none is passed.
in addition some providers of no customizable scope at all and either require it to be defined in the app settings, or offer no customization.

Update the readme to be clearer on which providers offer scope and those that don't.

Update the OAuth lib so it will auto populate the providers "basic" scope so it doesn't need to be defined in the config file.

Affected providers:

• Google
• Github
• Instagram
• Microsoft
• Soundcloud

[thomaswelton]

Google would require both the HTTP and HTTPs callback URL defined in the Redirect URIs, same may be true for other providers. Update readme

[thomaswelton]

Microsoft needed "wl.basic"
Instagram needed "basic"
Google needed "openid email" not comma seperated

[thomaswelton]

Some of these are in the readme https://github.com/Lusitanian/PHPoAuthLib/blob/master/src/OAuth/OAuth2/Service/Instagram.php#L16

Also see https://github.com/Lusitanian/PHPoAuthLib/blob/master/src/OAuth/OAuth2/Service/AbstractService.php#L190