chore: add constraints file (#1122)
Add constraints file to test lower bounds
diff --git a/testing/constraints-3.6.txt b/testing/constraints-3.6.txt
new file mode 100644
index 0000000..ccff147
--- /dev/null
+++ b/testing/constraints-3.6.txt
@@ -0,0 +1,13 @@
+# This constraints file is used to check that lower bounds
+# are correct in setup.py
+# List *all* library dependencies and extras in this file.
+# Pin the version to the lower bound.
+#
+# e.g., if setup.py has "foo >= 1.14.0, < 2.0.0dev",
+# Then this file should have foo==1.14.0
+httplib2==0.15.0
+google-auth==1.16.0
+google-auth-httplib2==0.0.3
+google-api-core==1.21.0
+six==1.13.0
+uritemplate==3.0.0
\ No newline at end of file