Update .podspec

Author: muukii

.swift-version

@@ -1,15 +1,16 @@
 Pod::Spec.new do |s|
   s.name             = "NextGrowingTextView"
-  s.version          = "1.4.1"
+  s.version          = "1.5.0"
   s.summary          = "The next in the generations of 'growing textviews' optimized for iOS 8 and above."
   s.homepage         = "https://github.com/muukii/NextGrowingTextView"
   s.license          = 'MIT'
   s.author           = { "muukii" => "[email protected]" }
   s.source           = { :git => "https://github.com/muukii/NextGrowingTextView.git", :tag => s.version.to_s }
-  s.social_media_url = 'https://twitter.com/muukii0803'
+  s.social_media_url = 'https://twitter.com/muukii_app'
 
   s.platform     = :ios, '8.0'
   s.requires_arc = true
+  s.swift_version = "5.1"
 
   s.source_files = 'NextGrowingTextView/**/*.swift'
 end