add in version.md for 2.7.0
add in version.md for 2.7.0

thevoiceofzeke/uw-frame,paulerickson/uw-frame,uPortal-Project/uportal-app-framework,thevoiceofzeke/uw-frame,apetro/uw-frame,paulerickson/uw-frame,thevoiceofzeke/uw-frame,UW-Madison-DoIT/uw-frame,paulerickson/uw-frame,UW-Madison-DoIT/uw-frame,apetro/uw-frame,UW-Madison-DoIT/uw-frame,uPortal-Project/uportal-app-framework,uPortal-Project/uportal-app-framework,apetro/uw-frame