[!] Unable to add a source with url `https://github.com/CocoaPods/Specs.git` named `master-1`.
You can try adding it manually in `~/.cocoapods/repos` or via `pod repo add`.
解決方案:
sudo xcode-select -switch /Applications/Xcode7.app (你想選擇的Xcode所在的路徑)
pod install