don't build test target except for testing

fix casting

Merge branch 'feature/instance'

change repository of Assertions

Merge pull request ishkawa#4 from ikesyo/early-termination

[RFC] Style: Early termination instead of using var

Merge pull request ishkawa#3 from ikesyo/enable-request-cancelation

[APIKit] Return NSURLSessionDataTask from `sendRequest` for cancelation

Merge pull request ishkawa#2 from ikesyo/result-helper-function

Use helper functions for Result

Merge pull request ishkawa#1 from ikesyo/fix-typo

[RequestBodyBuilder] Fix typo

Merge branch 'feature/HTTP-headers'

Merge branch 'feature/cocoapods'