Add Python 3.7 Linux wheels to artifact build

tools/run_tests/artifacts/artifact_targets.py

@@ -354,6 +354,7 @@ def targets():
         PythonArtifact('linux', 'x86', 'cp34-cp34m'),
         PythonArtifact('linux', 'x86', 'cp35-cp35m'),
         PythonArtifact('linux', 'x86', 'cp36-cp36m'),
+        PythonArtifact('linux', 'x86', 'cp37-cp37m'),
         PythonArtifact('linux_extra', 'armv7', '2.7'),
         PythonArtifact('linux_extra', 'armv7', '3.4'),
         PythonArtifact('linux_extra', 'armv7', '3.5'),
@@ -367,6 +368,7 @@ def targets():
         PythonArtifact('linux', 'x64', 'cp34-cp34m'),
         PythonArtifact('linux', 'x64', 'cp35-cp35m'),
         PythonArtifact('linux', 'x64', 'cp36-cp36m'),
+        PythonArtifact('linux', 'x64', 'cp37-cp37m'),
         PythonArtifact('macos', 'x64', 'python2.7'),
         PythonArtifact('macos', 'x64', 'python3.4'),
         PythonArtifact('macos', 'x64', 'python3.5'),