0.7.2-RC1

chorus(cherry-pick): merge commits from master to v0.7.x (#159)

* Fix a small typo in json tag of VolumeStats struct (#150)

Signed-off-by: Pablo Santiago Blum de Aguiar <scorphus@gmail.com>

* Fix typo: "happenes" is a misspelling of "happens" (#148)

Signed-off-by: Joseph Herlant <aerostitch@debian.org>

* [TA3796] fix(travis): update Dockerfile.dapper

This commit upgrades the docker version used to build the env
to latest stable ones.

Signed-off-by: Utkarsh Mani Tripathi <utkarshmani1997@gmail.com>

* Extracted common values and functions (#136)

Signed-off-by: Singh <gagandeep.singh@emc.com>

* Running gofmt -s (#149)

Signed-off-by: Joseph Herlant <aerostitch@debian.org>

* Minor changes to doc (#157)

Signed-off-by: Valerian Pereira <valerianpereira25@gmail.com>