Collect build logs in CircleCI artifacts.

regression.py

@@ -39,6 +39,8 @@ def build_me(folder):
     os.chdir(folder)
     try:
         res = os.system("./bui*.sh > build.log 2>&1 || exit 1")
+        is os.getenv("CIRCLE_ARTIFACTS") is not None:
+            os.system("cp build.log $CIRCLE_ARTIFACTS/" + folder + "_build.log")
         if res != 0:
             return folder, False, "Build failed..."
         if os.path.exists("regression.py"):