From the last Tor Project announce list:
One last reminder: Tor 0.2.4, 0.2.6, and 0.2.7 will no longer be
supported after 1 August of this year. Tor 0.2.8 will not be
supported after 1 Jan of 2018. Tor 0.2.5 will not be supported after
1 May of 2018. If you need a release with long-term support, 0.2.9 is
what we recommend: we plan to support it until at least 1 Jan 2020.
Would be nice to see a actual Tor version within the next updates.