This is fallout from de1bc894

Let's use a minor bump because dropping redundant constraints is
something that affects the type-signatures and could require to be
detectable in client-code via `MIN_VERSION_deepseq()`.

de1bc894 dropped a few redundant constraints, some of which are not yet
redundant in prior GHC/base versions.

[skip ci]

...and detabify deepseq.cabal file

This does not use ChasingBottoms as we're interested in testing each
field is evaluated exactly once which ChasingBottoms doesn't provide
afaics.

Specifically for `Data.Monoid.{Dual,First,Last,Any,All,Sum,Product}`

`--force-reinstalls` to avoid failures for GHC HEAD

Add `Generics`-backed `DefaultSignature` `rnf`-method

This also replaces the existing `rnf x = seq x ()` default
implementation with a `Generics`-based `DefaultSignature` `rnf` method
implementation

This requires to drop support for GHCs older than GHC 7.2 to avoid
conditional exports due to lack of `Generics` support

For more details, see original proposal

  http://permalink.gmane.org/gmane.comp.lang.haskell.libraries/23031

[skip ci]

As `deepseq` now hosted on GitHub, it now has its own Travis job to allow
validating PRs

This was broken in 3815fe81

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>

This also resurrects compatibility with older GHC versions back to
version 7.0.1 and specifies more accurate and verified build-depends.

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>