Can not get the latest version via pod install

I saw the latest version is 2.5.5 on https://cocoapods.org/?q=XCDYouTubeKit. However, the latest version I can find via pod command is 2.5.3. I've installed the latest version of cocoapod.

$ pod --version
1.2.0 

$ pod search XCDYouTubeKit
-> XCDYouTubeKit (2.5.3)
   YouTube video player for iOS and OS X.
   pod 'XCDYouTubeKit', '~> 2.5.3'
   - Homepage: https://github.com/0xced/XCDYouTubeKit
   - Source:   https://github.com/0xced/XCDYouTubeKit.git
   - Versions: 2.5.3, 2.5.2, 2.5.1, 2.5.0, 2.4.3, 2.4.2, 2.4.1, 2.4.0, 2.3.3, 2.3.2, 2.3.1, 2.3.0, 2.2.0, 2.1.3, 2.1.2, 2.1.1, 2.1.0, 2.0.3, 2.0.2, 2.0.1,
   2.0.0 [master repo]

Podfile

source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '10.0'

target 'MyProject' do
  use_frameworks!
  #...  
  pod 'XCDYouTubeKit', '~> 2.5'
end

If I change it to pod 'XCDYouTubeKit', '~> 2.5'.5, I get this:

[!] Unable to satisfy the following requirements:

- `XCDYouTubeKit (~> 2.5.5)` required by `Podfile`

None of your spec sources contain a spec satisfying the dependency: `XCDYouTubeKit (~> 2.5.5)`.

You have either:
 * out-of-date source repos which you can update with `pod repo update`.
 * mistyped the name or version.
 * not added the source repo that hosts the Podspec to your Podfile.

Note: as of CocoaPods 1.0, `pod repo update` does not happen on `pod install` by default.

0xced / XCDYouTubeKit

Can not get the latest version via pod install #320