[gnome-builder] tests: fix double assignment in Makefile.am

[Christian Hergert <chergert src gnome org>]

commit b6bed90253611a860fa28c7caea47aa9bc5b7d98
Author: Christian Hergert <chergert redhat com>
Date:   Tue Nov 8 00:32:37 2016 -0800

    tests: fix double assignment in Makefile.am

 tests/Makefile.am |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 77955d0..c47863a 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -91,7 +91,7 @@ test_ide_context_LDADD = $(tests_libs)
 test_ide_context_LDFLAGS = $(tests_ldflags)
 
 
-TESTS = test-ide-configuration
+TESTS += test-ide-configuration
 test_ide_configuration_SOURCES = test-ide-configuration.c
 test_ide_configuration_CFLAGS = $(tests_cflags)
 test_ide_configuration_LDADD = $(tests_libs)