[CI] Disable known bad mxnet nightly version (#997)

* Disallow mxnet 20191102 build

* !=0b20191102

* cpu only build for cpu tests

* Fix

Author: leezu

env/cpu/py3-master.yml

@@ -20,7 +20,7 @@ dependencies:
   - scipy=1.3.1
   - pip:
     - pylint-quotes==0.2.1
-    - mxnet-cu100>=1.6.0b20191027
+    - mxnet>=1.6.0b20191103
     - sacremoses
     - sentencepiece<0.2
     - sphinx-autodoc-typehints==1.7.0

env/gpu/py3-master.yml

@@ -30,7 +30,7 @@ dependencies:
   - scipy=1.3.1
   - pip:
     - pylint-quotes<0.2
-    - mxnet-cu100>=1.6.0b20191027
+    - mxnet-cu100>=1.6.0b20191027,!=1.6.0b20191102
     - sacremoses
     - sentencepiece<0.2
     - https://github.com/szha/mx-theme/tarball/master