Run Node distrib tests on Mac against only one Node version
diff --git a/tools/run_tests/distribtest_targets.py b/tools/run_tests/distribtest_targets.py
index fe26fd5..261f44b 100644
--- a/tools/run_tests/distribtest_targets.py
+++ b/tools/run_tests/distribtest_targets.py
@@ -240,10 +240,7 @@
           RubyDistribTest('linux', 'x64', 'ubuntu1504'),
           RubyDistribTest('linux', 'x64', 'ubuntu1510'),
           RubyDistribTest('linux', 'x64', 'ubuntu1604'),
-          NodeDistribTest('macos', 'x64', None, '0.12'),
-          NodeDistribTest('macos', 'x64', None, '3'),
           NodeDistribTest('macos', 'x64', None, '4'),
-          NodeDistribTest('macos', 'x64', None, '5'),
           NodeDistribTest('linux', 'x86', 'jessie', '4')
           ] + [
             NodeDistribTest('linux', 'x64', os, version)