goPackages.inflect: add version suffix

Instead of approach in #12002, I chose the commit-date style
to preserve linearity if it (ever) gets updates.
The package seems to do no releases.

pkgs/top-level/go-packages.nix

···
   };
 
   inflect = buildGoPackage {
-    name = "inflect";
+    name = "inflect-2013-08-29";
     goPackagePath = "bitbucket.org/pkg/inflect";
     src = fetchFromBitbucket {
       rev    = "8961c3750a47b8c0b3e118d52513b97adf85a7e8";