[Haskell-cafe] ANN: stack-1.5.1 released

See https://haskellstack.org for installation and upgrade instructions. Bug fixes: * Stack eagerly tries to parse all cabal files related to a snapshot. Starting with Stackage Nightly 2017-07-31, snapshots are using GHC 8.2.1, and the `ghc.cabal` file implicitly referenced uses the (not yet supported) Cabal 2.0 file format. Future releases of Stack will both be less eager about cabal file parsing and support Cabal 2.0. This patch simply bypasses the error for invalid parsing.