[commit: ghc] master: Update transformers submodule to 0.5.1.0 release (9b71695)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/9b716950e1c9e99afe2840ef804e5b3343ef3653/ghc

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commit 9b716950e1c9e99afe2840ef804e5b3343ef3653
Author: Herbert Valerio Riedel <hvr at gnu.org>
Date:   Tue Jan 26 12:03:23 2016 +0100

    Update transformers submodule to 0.5.1.0 release
    
    This shouldn't have any noticeable API changes for GHC


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9b716950e1c9e99afe2840ef804e5b3343ef3653
 libraries/transformers | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/transformers b/libraries/transformers
index 1a2bc4e..a2f7dd0 160000
--- a/libraries/transformers
+++ b/libraries/transformers
@@ -1 +1 @@
-Subproject commit 1a2bc4ecada9561911e9c2e8a98a3c6bf59b7bb1
+Subproject commit a2f7dd057a0ee0c6cb206609594d7a07d26a1861