tag v1.2.0

Fix error for workflows

Merge pull request emqx#89 from emqx/improve-frame

Remove the '{error, Reason}' function clause

Add more test cases for emqtt (emqx#80)

* Add more test cases for emqtt

* Delete useless comments

Use git tag to control vsn and delete maintainers

Due to the limit of hex plugin, we have to delete
maintainers to make rebar3 hex publish succeed

Rm reuseaddr config

Rm reuseaddr config

Rm reuseaddr config