Merge pull request iZettle#244 from iZettle/version_2.1

SDK version 2.1

Merge pull request iZettle#239 from iZettle/version_2.0.5

SDK version 2.0.5

Merge pull request iZettle#234 from iZettle/version_2.0.4

SDK version 2.0.4

Merge pull request iZettle#231 from iZettle/version_2.0.3

SDK Release v2.0.3

Merge pull request iZettle#229 from iZettle/version_2.0.2

SDK Release 2.0.2

Merge pull request iZettle#221 from iZettle/carhtage-2.0.1

Update Carthage with 2.0.1 release

Merge pull request iZettle#216 from iZettle/version_2.0

SDK Release v2.0

Merge pull request iZettle#195 from iZettle/version_1.7.1

SDK Release [v1.7.1]

Merge pull request iZettle#190 from iZettle/issue-template

Add issue template

Merge pull request iZettle#164 from iZettle/version_1.6.1

SDK version 1.6.1