ghc-cabal-doctest-1.0.6-bp151.2.2

- Update Cabal build instructions to support ghc-8.6.1.

- Cosmetic: replace tabs with blanks, strip trailing white space,
  and update copyright headers with spec-cleaner.

- Update cabal-doctest to version 1.0.6 revision 1.
  * Hook `haddock` build too. Fixes issue when `haddock` fails, as
    `Build_doctests` isn't generated.
  * Add a hack so `Build_doctests` module is automatically added to
    to `other-modules` and `autogen-modules` when compiled with Cabal-2.0.
    Thanks to that, we don't get warnings because of `-Wmissing-home-modules`.
  * Add support for doctests in executables and (with `Cabal-2.0` or later)
    internal libraries. Refer to the `README` for more details.
  * Add an explicit `Prelude` import to `Build_doctests`

- Updated with latest spec-cleaner version 0.9.8-8-geadfbbf.

- Update to version 1.0.2 with cabal2obs.

- Update to version 1.0.1 with cabal2obs.

- Update to version 1 with cabal2obs.