CocoaPods installation test fails — Twitter is not reachable

[1ec5]

As of yesterday, the Xcode_10.2_iOS_12.2_CP_update build bot has started failing because all pods fail to lint. pod lib lint checks reachability of any URL in the podspec, including the social media URL:

mapbox-navigation-ios/MapboxNavigation.podspec

Line 23 in b1c7f6c

s.social_media_url = "https://twitter.com/mapbox"

However CocoaPods checks for reachability, a Twitter site redesign is breaking it: CocoaPods/CocoaPods#9049.

firebase/firebase-ios-sdk#3418 is probably close to what we’ll need to do in the interim: remove the social media URL from the podspec while linting.

/cc @mapbox/ios

[1ec5]

#2188 removes the social media URL for the tests, but for now, when releasing, we’ll need to use --allow-warnings.