This post goes over how to set Cocoapods to a specific version:
List
Display Cocoapods version:
pod --version
Check if you have multiple versions of Cocoapods installed:
gem list cocoapods
If you see something like:
*** LOCAL GEMS ***
cocoapods (1.16.2, 1.14.3, 1.11.3)
Then you might want to delete the other versions.
Install
Install Cocoapods version 1.14.3:
sudo gem install cocoapods -v 1.14.3
Uninstall
Uninstall Cocoapods version:
sudo gem uninstall cocoapods