Don't include examples in the npm package (#60)

Do not include the examples while creating npm package
* Include .gitignore content in .npmignore

.npmignore

@@ -0,0 +1,42 @@
+# Xcode
+!**/*.xcodeproj
+!**/*.pbxproj
+!**/*.xcworkspacedata
+!**/*.xcsettings
+!**/*.xcscheme
+*.pbxuser
+!default.pbxuser
+*.mode1v3
+!default.mode1v3
+*.mode2v3
+!default.mode2v3
+*.perspectivev3
+!default.perspectivev3
+xcuserdata
+*.xccheckout
+*.moved-aside
+DerivedData
+*.hmap
+*.ipa
+*.xcuserstate
+project.xcworkspace
+
+# Xcode, Gradle
+build/
+
+# Android
+.idea
+.gradle
+local.properties
+*.iml
+
+# Node
+node_modules
+*.log
+.nvm
+
+# OS X
+.DS_Store
+
+# examples is not required in npm package
+examples/