prepare for release

web3swift.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
 s.name             = "web3swift"
-s.version          = "0.8.1"
+s.version          = "0.9.0"
 s.summary          = "Web3 implementation in vanilla Swift for iOS ans macOS"
 
 s.description      = <<-DESC
@@ -16,7 +16,7 @@ s.social_media_url = 'https://twitter.com/shamatar'
 s.swift_version = '4.1'
 s.module_name = 'web3swift'
 s.ios.deployment_target = "9.0"
-s.osx.deployment_target = "10.13"
+s.osx.deployment_target = "10.11"
 s.source_files = "web3swift/**/*.{h,swift}", 
 s.public_header_files = "web3swift/**/*.{h}"
 s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES' }
@@ -29,5 +29,5 @@ s.dependency 'Result', '~> 3.0.0'
 s.dependency 'CryptoSwift', '~> 0.10.0'
 s.dependency 'libsodium', '~> 1.0.12'
 s.dependency 'secp256k1_ios', '~> 0.1.3'
-
+s.dependency 'PromiseKit', '~> 6.3.0'
 end