no py-3.8 build for tf-1.14 and lower

Author: guschmue

ci_build/azure_pipelines/pretrained_model_test-matrix.yml

@@ -4,7 +4,7 @@ jobs:
 - template: 'templates/job_generator.yml'
   parameters:
     platforms: ['linux', 'windows']
-    python_versions: ['3.8', '3.6']
+    python_versions: ['3.6']
     tf_versions: ['1.13.1', '1.12.3']
     job:
       steps:
@@ -13,7 +13,7 @@ jobs:
 - template: 'templates/job_generator.yml'
   parameters:
     platforms: ['linux', 'windows']
-    python_versions: ['3.8', '3.7', '3.6']
+    python_versions: ['3.7', '3.6']
     tf_versions: ['1.14.0']
     job:
       steps:

ci_build/azure_pipelines/unit_test-matrix.yml

@@ -6,7 +6,7 @@ stages:
     - template: 'templates/job_generator.yml'
       parameters:
         platforms: ['linux', 'windows']
-        python_versions: ['3.7', '3.6']
+        python_versions: [3.6']
         tf_versions: ['1.13.1', '1.12.3']
         onnx_opsets: ['']
         job:
@@ -17,7 +17,7 @@ stages:
     - template: 'templates/job_generator.yml'
       parameters:
         platforms: ['linux', 'windows']
-        python_versions: ['3.8', '3.7', '3.6']
+        python_versions: ['3.7', '3.6']
         tf_versions: ['1.14.0']
         onnx_opsets: ['']
         job:

ci_build/azure_pipelines/unit_test.yml

@@ -5,7 +5,7 @@ stages:
     jobs:
     - template: 'templates/job_generator.yml'
       parameters:
-        python_versions: ['3.8', '3.7', '3.6']
+        python_versions: ['3.7', '3.6']
         tf_versions: ['1.14.0']
         onnx_opsets: ['']
         job:
@@ -15,7 +15,8 @@ stages:
 
     - template: 'templates/job_generator.yml'
       parameters:
-        tf_versions: ['1.14.0', '1.12.3']
+        python_versions: [3.6']
+        tf_versions: ['1.12.3']
         onnx_opsets: ['']
         job:
           steps: