We may bump to 0.2 version as soon as possible

[driftluo]

• The 0.1 version has an error not reported to the user Report open proto failed #54
• There is a type of error using Report open proto failed #54
• Lack of defense against fd attacks, need a timeout error Report open proto failed #54 Report session timeout #57
• Some users want to be able to support event stream output instead of callback，0.2 should support both programming modes at the same time Support event output #58
• Let user control turn protocol on and off, breaking change Give protocol permission to user #62
• May need to support each protocol has their own codec, and does not require the same structure(trait object) Support multi-codec #63
• Add poll API to all protocol handle, to allow users to customize some stream tasks in the handle Support handle customize poll #65

release 0.2.0-alpha.1

• Abstract transport layer Abstract transport layer #76
• Maybe there are other problems, let us wait and see in the evolution process.

[driftluo]

close by #158