check_version.sh needs latest pip per https://travis-ci.community/t/11214 (#345)

Author: DanielGoldfarb

Diff for: scripts/check_version.sh

@@ -11,6 +11,9 @@ then
 fi
 
 echo "PR: branch passed in: $pr_branch"
+# make sure we have the latest pip:
+pip3 install --upgrade pip  
+
 git fetch origin +refs/pull/${pr_branch}/merge
 git checkout FETCH_HEAD
 pip3 install .
@@ -30,4 +33,4 @@ then
     echo "${result}"
     exit 1
 fi
-echo "VersionCheck PASSED with response: ${result}"
+echo "VersionCheck PASSED with response: ${result}"