Specify Pod Versions in Test Target
Specify Pod Versions in Test Target

`OHHTTPStubs` was updated to v4.2.0 and removed a method which was used in the
spec. This resulted in a failing build.

This patch specifies versions for Pods and sets `OHHTTPStubs` to v4.1.0 to get
a stable build.

trustedshops/trustbadge_iOS,trustedshops/trustedshops-ios-sdk,trustedshops/trustedshops-ios-sdk,trustedshops/trustedshops-ios-sdk