The following four numpy op tests fails with numpy==1.19

• test_np_delete
• test_np_random_beta
• test_np_random_f
• test_np_random_chisquare

The failure happens on the master branch CI http://jenkins.mxnet-ci.amazon-ml.com/blue/organizations/jenkins/mxnet-validation%2Fwindows-cpu/detail/master/2034/pipeline and blocks recent PRs http://jenkins.mxnet-ci.amazon-ml.com/blue/organizations/jenkins/mxnet-validation%2Fwindows-cpu/detail/PR-18598/7/pipeline

It only happens recently, and I noticed that the installed numpy version on CI has changed from numpy-1.18.5 to numpy-1.19.0 - see installation log in previous commit and master head.
Also notice that the error log shows that the exceptions happen in the _np.xx functions, which is part of the official numpy APIs instead of mx.numpy APIs.

@yzhliu FYI