According to "code conventions" [1], do not use "-y" option.
Instead, use apt-get install package, yum install package,
or zypper install package.
[1] https://docs.openstack.org/doc-contrib-guide/writing-style/
code-conventions.html
Change-Id: I421578ed2acae15c9f6eef2a6f0013090fdb7acc