Enhance the test coverage part-13 : dubbo-remoting/dubbo-remoting-api(dubbo-remoting-grizzly|dubbo-remoting-http) modules

[lovepoem]

add unit test to the modules
dubbo-remoting/dubbo-remoting-api
dubbo-remoting/dubbo-remoting-grizzly/
dubbo-remoting/dubbo-remoting-http/

[dreamquster]

@lovepoem I will pick up this.

[lovepoem]

@dreamquster ok ，it's yours

[lovepoem]

This issue has been around for a while. What is the progress now? Please give me a feedback.

[htynkn]

for module dubbo-remoting-http, the test coverage is 73.59%
for module dubbo-remoting-api, the test coverage is 57.22%
but for module dubbo-remoting-grizzly, it's zero.

so we still need someone working on this task, but let's focus on module dubbo-remoting-grizzly