disable update pip?

.travis.yml

@@ -3,26 +3,26 @@
 language: python            # this works for Linux but is an error on macOS or Windows
 matrix:
   include:
-    - name: "Python 3.7.1 on Bionic Ubuntu"
+    - name: "Python 3.7 on Bionic Ubuntu"
       python: 3.7           # this works for Linux but is ignored on macOS or Windows
       dist: bionic          # required for Python >= 3.7
 
-    - name: "Python 3.7.2 on macOS xcode10."
+    - name: "Python 3.7 on macOS xcode10."
       os: osx
       osx_image: xcode10.2  # Python 3.7.2 running on macOS 10.14.3
       language: shell       # 'language: python' is an error on Travis CI macOS
       # python: 3.7         # 'python:' is ignored on Travis CI macOS
       before_install: python3 --version ; pip3 --version ; sw_vers
 
-    - name: "Python 3.7.3 on Windows"
+    - name: "Python 3.7 on Windows"
       os: windows           # Windows 10.0.17134 N/A Build 17134
       language: shell       # 'language: python' is an error on Travis CI Windows
       # python: 3.7         # 'python:' is ignored on Travis CI Windows
       before_install:
         - choco install python  # this install takes at least 1 min 30 sec
-        - python -m pip install --upgrade pip
+        # - python -m pip install --upgrade pip
       env: PATH=/c/Python37:/c/Python37/Scripts:$PATH
-install: pip3 install --upgrade pip  # all three OSes agree about 'pip3'
+#install: pip3 install --upgrade pip  # all three OSes agree about 'pip3'
 
 # 'python' points to Python 2.7 on macOS but points to Python 3.7 on Linux and Windows
 # 'python3' is a 'command not found' error on Windows but 'py' works on Windows only