added campaignmonitor to composer

Signed-off-by: Ninjaparade <ninja@ninjaparade.ca>
added config

Signed-off-by: Ninjaparade <ninja@ninjaparade.ca>
added Mailchimp class

Signed-off-by: Ninjaparade <ninja@ninjaparade.ca>
added config

Signed-off-by: Ninjaparade <ninja@ninjaparade.ca>
added interface

Signed-off-by: Ninjaparade <ninja@ninjaparade.ca>