PostmarkClient@getSuppressions returns PostmarkSuppressionResultList instead of PostmarkSuppressionList

[ashgibson]

As per title. It appears the the PostmarkClient@getSuppressions function is incorrectly returning a PostmarkSuppressionResultList instead of a PostmarkSuppressionList.

PostmarkSuppressionResultList should be used for the return value of creating suppressions and PostmarkSuppressionList should be used when querying suppressions

Have created pull request - #126

[ewood-ac]

I have approved this change.

[ashgibson]

Can a new release be created with this fix please.

[ewood-ac]

Sorry for the delay. I have that out now.