Add 7.8.4, 7.10.2 and 7.10.3 to travis matrix

[phadej]

No description provided.

[phadej]

Last commit is optional, but I'd advice to have upper bounds.

[killy971]

For some reason I can't remember (might have been an article I read a while back), I had the impression that it was not such a good idea to add upper bounds, but maybe it was my misunderstanding.

Is it still a common practice to set upper bounds these days?

Also, how should the upper bound value be defined?
Is this a case by case decision?

[phadej]

One good answer on top of my head is haskell/cabal#2774 (comment) (related discussion before and after is worth reading if you have time).

So upper bounds here are forbidding next major release of each depedency, which might introduce breaking changes affecting hpc-hoveralls, like retry-0.7 did. This for example caused travis builds of purescript fail for no reason, that's how I found an issue with hpc-hoveralls.