Include standard out/error output in exception output

The pre-commit hook context would only include output from standard
error when an exception occurred. Unfortunately, this sometimes leaves
out important information for debugging purposes.

Include both streams in the output to aid in debugging.

Change-Id: Ib38348174c983d7133721120c64af6cba8f0254e
Reviewed-on: http://gerrit.causes.com/42177
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane.dasilva@brigade.com>

Author: sds

CHANGELOG.md

@@ -10,6 +10,8 @@
   contained decimals
 * Warn when trying to pipe commands using the `execute` helper, as this is not
   supported
+* Include both standard out/error streams in exception messages in pre-commit
+  hook context
 
 ## 0.16.0
 

lib/overcommit/hook_context/pre_commit.rb

@@ -28,7 +28,7 @@ def setup_environment
           # issue (e.g. author/email not set or GPG signing key incorrect)
           raise Overcommit::Exceptions::HookSetupFailed,
                 "Unable to setup environment for #{hook_script_name} hook run:" \
-                "\n#{result.stderr}"
+                "\nSTDOUT:#{result.stdout}\nSTDERR:#{result.stderr}"
         end
 
         @changes_stashed = true
@@ -75,7 +75,7 @@ def clear_working_tree
       unless result.success?
         raise Overcommit::Exceptions::HookCleanupFailed,
               "Unable to cleanup working tree after #{hook_script_name} hooks run:" \
-              "\n#{result.stderr}"
+              "\nSTDOUT:#{result.stdout}\nSTDERR:#{result.stderr}"
       end
     end
 
@@ -85,7 +85,7 @@ def restore_working_tree
       unless result.success?
         raise Overcommit::Exceptions::HookCleanupFailed,
               "Unable to restore working tree after #{hook_script_name} hooks run:" \
-              "\n#{result.stderr}"
+              "\nSTDOUT:#{result.stdout}\nSTDERR:#{result.stderr}"
       end
     end