[Podspec] Fixes podspec.

RxNimble.podspec

@@ -9,12 +9,12 @@ Pod::Spec.new do |s|
   s.license      = { :type => "MIT", :file => "LICENSE" }
   s.author             = { "Ash Furrow" => "ash@ashfurrow.com" }
   s.social_media_url   = "http://twitter.com/ashfurrow"
-  s.ios.deployment_target = "7.0"
+  s.ios.deployment_target = "8.0"
   s.osx.deployment_target = "10.9"
   s.tvos.deployment_target = "9.0"
   s.source       = { :git => "https://github.com/ashfurrow/RxNimble.git", :tag => s.version }
   s.source_files  = "Source/**/*.swift"
-  s.dependency "Nimble", "~> 3.0.0"
-  s.dependency "RxSwift", "~> 2.0.0"
-  s.dependency "RxBlocking", "~> 2.0.0"
+  s.dependency "Nimble", "~> 3.0"
+  s.dependency "RxSwift", "~> 2.0"
+  s.dependency "RxBlocking", "~> 2.0"
 end