`IKEventSource` does not specify a Swift version

[Mohamed-Afsar]

Projects which have been written purely in ObjC face this issue while installing EventSource using CocoaPods.

Error Log:

[!] Unable to determine Swift version for the following pods:

• IKEventSource does not specify a Swift version and none of the targets (<ProjectName>) integrating it have the SWIFT_VERSION attribute set. Please contact the author or set the SWIFT_VERSION attribute in at least one of the targets that integrate this pod.

Adding s.swift_version = 'version' in podspec will solve the issue, I guess.