Update Vaccine.podspec

Merge pull request #53 from zenangst/improve/injecting-child-view-con…

…trollers-on-macos

Improve injecting child view controllers on macOS

Merge pull request #52 from zenangst/improve/not-loading-injection-in…

…-release

Add extra constraint to not load injection unless the main bundle is in derived data

Merge pull request #51 from zenangst/improve/using-view-controllers-w…

…ith-nibs

Improve using Vaccine with nibs/xibs

Merge pull request #50 from zenangst/fix/4.0

Make Vaccine compatible with Swift 4.0

Bump version number to 0.13.3

Merge pull request #49 from zenangst/fix/crash-on-mac-os-when-selecti…

…ng-text

Use the view setter instead of init(nibName:bundle:)

Merge pull request #48 from zenangst/improve/removing-constraints-fro…

…m-views

Improve removing constraints from views

Merge pull request #47 from zenangst/feature/animations-on-mac-os

Implement support for animated injections on macOS

Merge pull request #46 from zenangst/improve/injecting-nsviewcontrollers

Improve injecting NSViewControllers