Added CocoaPod support

.swift-version

@@ -0,0 +1 @@
+4.0

ZIPFoundation.podspec

@@ -0,0 +1,17 @@
+Pod::Spec.new do |s|
+  s.name = 'ZIPFoundation'
+  s.version = '0.9.0'
+  s.license = 'MIT'
+  s.summary = 'Effortless ZIP Handling in Swift'
+  s.homepage = 'https://github.com/weichsel/ZIPFoundation'
+  s.social_media_url = 'http://twitter.com/weichsel'
+  s.authors = { 'Thomas Zoechling' => 'thomas@peakstep.com' }
+  s.source = { :git => 'https://github.com/weichsel/ZIPFoundation.git', :tag => s.version }
+
+  s.ios.deployment_target = '9.0'
+  s.osx.deployment_target = '10.11'
+  s.tvos.deployment_target = '9.0'
+  s.watchos.deployment_target = '2.0'
+
+  s.source_files = 'Sources/ZIPFoundation/*.swift'
+end