update readme

* github issues #6
* use rake version > 10

README.md

@@ -8,6 +8,8 @@ See `examples`.
 
 ## Dev
 
+I am using Ruby 2.4 develop this gem, if not work with other Ruby version, PR is welcome.
+
 ```shell
 #!/bin/sh
 
@@ -40,6 +42,10 @@ protoc -I ${PULSAR_GIT}/pulsar-common/src/main/proto/ --ruby_out ${PB_PATH} Puls
 mv ${PB_PATH}PulsarMarkers_pb.rb ${PB_PATH}pulsar_markers.pb.rb
 ```
 
+## Dependency
+
+When macOS user install google-protobuf, there maybe a suffix with `universal-darwin` save to Gemfile.lock. Please use google-protobuf without `universal-darwin` suffix. See issuse #6 for detail. Thanks for wppurking's report!
+
 ## Features
 
 - [ ] Connection
@@ -79,6 +85,8 @@ mv ${PB_PATH}PulsarMarkers_pb.rb ${PB_PATH}pulsar_markers.pb.rb
   - [ ] Create
 - [ ] Admin API
   - [x] Create Namespace
+  - [x] List namespaces in current tenant
+  - [x] Destroy Namespace
   - [x] List Namespace Topics
   - [x] Create Topic
   - [x] Delete Topic

pulsar_sdk.gemspec

@@ -27,5 +27,5 @@ Gem::Specification.new do |spec|
   spec.add_dependency 'digest-crc', '~> 0.4'
 
   spec.add_development_dependency "bundler", "> 1.17"
-  spec.add_development_dependency "rake", "~> 10"
+  spec.add_development_dependency "rake", "> 10"
 end