【iOS】CocoaPods 升级到v1.0.0后pod install 出错The dependency `**` is not used in any concrete target

v1.0.0版本CocoaPods之后pod install 报错：

[!] The dependency `RxSwift (~> 2.5.0)` is not used in any concrete target.
The dependency `RxCocoa (~> 2.5.0)` is not used in any concrete target.
The dependency `SnapKit (~> 0.30.0.beta1)` is not used in any concrete target.

我的Podfile内容：

platform :ios, '8.0'
use_frameworks!
pod 'RxSwift',  '~>2.5'
pod 'RxCocoa', '~> 2.5.0'
pod 'SnapKit', '~> 0.30.0.beta1'    

原来新版本CocoaPods强制要求Podfile必须指明target，否则报错，Podfile内容修改为：

target '**' do
  platform :ios, '8.0'
  use_frameworks!
  pod 'RxSwift',  '~>2.5'
  pod 'RxCocoa', '~> 2.5.0'
  pod 'SnapKit', '~> 0.30.0.beta1'   
end 

即可！

注：文中如有任何错误，请各位批评指正！