Update podspec for 1.4.0 release

Author: nvzqz

FileKit.podspec

@@ -1,12 +1,12 @@
 Pod::Spec.new do |s|
     s.name                  = "FileKit"
-    s.version               = "1.3.0"
+    s.version               = "1.4.0"
     s.summary               = "Simple and expressive file management in Swift."
     s.homepage              = "https://github.com/nvzqz/FileKit"
     s.license               = { :type => "MIT", :file => "LICENSE.md" }
     s.author                = "Nikolai Vazquez"
     s.ios.deployment_target = "8.0"
     s.osx.deployment_target = "10.9"
-    s.source                = { :git => "https://github.com/nvzqz/FileKit.git", :tag => "v1.3.0" }
+    s.source                = { :git => "https://github.com/nvzqz/FileKit.git", :tag => "v1.4.0" }
     s.source_files          = "FileKit/*/*.swift"
 end

README.md

@@ -53,7 +53,7 @@ to learn more.
     ```
     use_frameworks!
 
-    pod 'FileKit', '~> 1.3.0'
+    pod 'FileKit', '~> 1.4.0'
     ```
 
 2. Run `pod install` and open the `.xcworkspace` file to launch Xcode.