As per #716, GHC-7 support has at the moment no priority. Use the GHC7 tag
for the last version that retains the original GHC-7.10 support.

https://github.com/gibiansky/IHaskell/releases/tag/GHC7

(However, it is still quite feasible to support GHC-7.10 in master, see
#747.)