Add podspec from main repo

Author: bjtitus

RSOAuthEngine.podspec

@@ -0,0 +1,13 @@
+Pod::Spec.new do |s|
+  s.name = 'RSOAuthEngine'
+  s.version = '1.0.0'
+  s.license = 'MIT'
+  s.summary = 'ARC based OAuth engine for MKNetworkKit.'
+  s.homepage = 'https://github.com/rsieiro/RSOAuthEngine'
+  s.authors = { 'Rodrigo Sieiro' => '[email protected]' }
+  s.source = {:git => 'https://github.com/rsieiro/RSOAuthEngine.git', :tag => '1.0.0'}
+  s.source_files = 'RSOAuthEngine/*.{h,m}'
+
+  s.requires_arc = true
+  s.dependency 'MKNetworkKit'
+end