Enhance Apple Pay authorization with presented callback

• added onPresented: (Optional) The block to be called once the Apple Pay sheet is presented to the user

Full Changelog: 1.0.30...1.0.31

Sending MID in token request

1.0.30

Merge pull request #3 from Tap-Payments/FT_update_merchant_id_tap_app…

Cancel callback

1.0.29

Bump version to 1.0.29 in podspec

Removing .emv encryption as a default capabilities

1.0.28

Removing .emv from default capabilities

Updated code snippet for ApplePay capabilities

1.0.27

Updating to latest applepay capabilities code.

New token request payload

1.0.26

Default mode back to sandbox

Support Tap Merchant ID

1.0.25

Adding Tap Merchant ID

Removing unused code

1.0.24

Merge pull request #1 from Tap-Payments/FT_get_view_controller_from_d…

Production.

1.0.23

Point to production.

Ability to pass the payment options when using apis not our pay button

1.0.22

Ability to pass the payment options when using apis not our pay button