Add lower bound to tasty-ant-xml

[jneira]

• The pr adding tast-ant-xml was built succesfullt with cabal in ci
  • It used:

 - tasty-1.2.3 (lib) (requires download & build)
 - tasty-rerun-1.1.17 (lib) (requires download & build)
 - tasty-hunit-0.10.0.2 (lib) (requires download & build)
 - tasty-expected-failure-0.11.1.2 (lib) (requires download & build)
 - tasty-ant-xml-1.1.6 (lib) (requires download & build)

• The next commit (mine! ✋ ) changed the hackage index from 2020-05-13T21:21:45Z to 2020-05-17T20:25:21Z and triggered the build error picking;

 - tasty-1.3.1 (lib) (requires download & build)
 - tasty-rerun-1.1.17 (lib) (requires download & build)
 - tasty-hunit-0.10.0.2 (lib) (requires download & build)
 - tasty-expected-failure-0.11.1.2 (lib) (requires download & build)
 - tasty-ant-xml-1.0.0.5 (lib) (requires download & build)

Not sure what is going on but adding a lower bound force cabal to pick the good version. Tested locally for ghc-8.6.4, ghc-8.6.5, ghc-8.8.3 y ghc-8.10.1

[jeffwindsor]

@jneira not absolutely sure the reason, my best guess is that it something to do with the way tasty-ant-xml defines its dependency to tasty with an upper bound, but not really sure how that is confusing anything.

[jneira]

@jeffwindsor thanks for review this, the cabal build is green again and the stack ones are failing running tests as usual so merging this