Travis: remove 4.06 allow_failures rows

Lwt, all its dependencies, and all helper libraries now build on 4.06.

[skip appveyor]

Author: aantron

.travis.yml

@@ -26,10 +26,6 @@ matrix:
     - os: osx
       env: COMPILER=4.03 PACKAGE_MANAGER=macports LIBEV=no
 
-  allow_failures:
-    - env: COMPILER=4.06 FLAMBDA=yes
-    - env: COMPILER=4.06 FLAMBDA=yes LIBEV=no
-
 env:
   global:
     - LWT_FORCE_LIBEV_BY_DEFAULT=yes