chore: update podspec tag to 0.4.0

Author: Tom Bachant

InitialsImageView.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = "InitialsImageView"
-  s.version      = "0.3.0"
+  s.version      = "0.4.0"
   s.summary      = "A simple UIImageView extension for using initials as a profile image, written in swift"
   s.description  = "An easy, helpful UIImageView extension that generates letter initials as a placeholder for user profile images, with a randomized background color."
   s.homepage     = "https://github.com/bachonk/InitialsImageView"
@@ -9,7 +9,7 @@ Pod::Spec.new do |s|
   s.author       = { "Tom Bachant" => "tom@dashride.com" }
   s.platform     = :ios, '8.0'
   s.source = { :git => "https://github.com/bachonk/InitialsImageView.git",
-               :tag => '0.3.0' }
+               :tag => '0.4.0' }
   s.source_files  = 'InitialsImageView.swift'
   s.requires_arc = true
   s.swift_version = '4.2'