sanity_tested_distro: Add Ubuntu-14.04 and remove other unsupported hosts

JIRA: SB-3254

We currently support ubuntu-12.04 LTS and ubuntu-14.04 LTS distro.
Removed EOL (ubuntu-12.10, ubuntu-13.04 & Fedora 18,19) OS's from list

Signed-off-by: Srikanth Krishnakar <Srikanth_Krishnakar@mentor.com>
Merge pull request #264 from skrishnakar/sanity-tested-distros

sanity_tested_distro: Add Ubuntu-14.04 and remove other unsupported hosts