Remade podspec

Remade podspec so it sits more inline with standard podspec, takes most infomation from package.json

react-native-nfc-manager.podspec

@@ -0,0 +1,18 @@
+require "json"
+
+json = File.read(File.join(__dir__, "package.json"))
+package = JSON.parse(json).deep_symbolize_keys
+
+Pod::Spec.new do |s|
+  s.name = package[:name]
+  s.version = package[:version]
+  s.license = { type: "MIT" }
+  s.homepage = "https://github.com/whitedogg13/react-native-nfc-manager"
+  s.authors = package[:author]
+  s.summary = package[:description]
+  s.source = { git: package[:repository][:url] }
+  s.source_files = "ios/**/*.{h,m}"
+  s.platform = :ios, "8.0"
+
+  s.dependency "React"
+end