Bump package bounds

[vmchale]

This allows threadscope to be built with GHC 8.6.4

[Mikolaj]

Hmm, it looks like the travis script bit-rotted (possibly cabal new-build now works differently?).

[vmchale]

For some reason the Mac CI script is still failing.

[Mikolaj]

@maoe: any hints?

[maoe]

Let me check. I'll regenerate .travis.yml.

[osa1]

@maoe any news?

The osx failures seems to be because of a missing libffi dependency. Should it be installed system-wide somehow before starting the build?

[maoe]

@osa1 Sorry I've got sidetracked. I'm working on this at update-travis...maoe:update-travis. I think I'll have some time to continue this later today.

[maoe]

Status update: I'm currently waiting for gtk2hs/gtk-mac-integration#8 to be resolved. Once it's fixed, update-travis...maoe:update-travis should work fine.

If it's not resolved in a few days, we probably want to restrict os(darwin) to older GHCs.

In the long run, I guess it's maybe better to migrate ThreadScope from gtk2hs to haskell-gi. I thought I had a WIP branch somewhere for this but I forgot the status of it.

[maoe]

I just merged #99 which contained some of the commits from this PR. Thanks for your contribution.