Python: refactor installing unit/system test dependencies #1185
Description
- Rather than using the template langage to generate
session.installcommands innoxfile.py, use simplers form to generate a standard set of variables at the top of the file. - Break out installing dependencies in to separate helper functions using those variables, called by the
unit/systemsessions. - Pass in the constraints explicitly to the helper functions, to allow for future sessions (e.g., passing
--preas a constraint, see Client libraries need out-of-band tests against prereleases of third party dependencies google-cloud-python#10578).
tswast