gitpod: Update pip

Author: John Andersen

.gitpod.yml

@@ -1,4 +1,4 @@
 image:
     file: scripts/gitpod.Dockerfile
 tasks:
-  - init: pip install -e .[dev] && dffml service dev install && echo -e '#!/bin/sh\nexec python3.7 -m black --check .' > .git/hooks/pre-commit && chmod 755 .git/hooks/pre-commit
+  - init: pip install -U pip && pip install -e .[dev] && dffml service dev install && echo -e '#!/bin/sh\nexec python3.7 -m black --check .' > .git/hooks/pre-commit && chmod 755 .git/hooks/pre-commit