Merge pull request #160 from resouer/fix-centos-version

Fix centos version to 7.*

Merge pull request #146 from feiskyer/fix-rbd

Fix rbd map for ceph Jewel

Merge pull request #143 from resouer/file

Restore DESIGN.md

Release v1.2.0

Update hyper minimum version to v0.6.0

Merge pull request #82 from feiskyer/update-exec

Fix hyper exec and attach

Merge pull request #20 from carmark/test

first round test cases fix