Prep runtimeconfig-0.25.0 release.

[tseaver]

Requires merge of #3526 to bump core to 0.25.0.

Draft release notes:

google-cloud-runtimeconfig-0.25.0

• Update google-cloud-core dependency to ~= 0.25.

---

Excluded from notes:

• Re-enable pylint in info-only mode for all packages (Re-enable pylint in info-only mode for all packages #3519)
• Vision semi-GAPIC (Vision semi-GAPIC #3373)
• Ignore tests (rather than unit_tests) in setup.py files. (Ignore tests (rather than unit_tests) in setup.py files. #3319)
• Adding check that all setup.py README's are valid RST. (Adding check that **all** setup.py README's are valid RST. #3318)

[dhermes]

@tseaver I'm not sure about the use of ~ (I presume to mean approximately?) How about instead:

Update google-cloud-core dependency to 0.25.x series?

[tseaver]

I meant to be using ~=, in the PEP 440 sense.

[dhermes]

I'm not sure many people know ~= in the PEP 440 sense. I've read PEP 440 and I don't.

[tseaver]

AFAIK, it is what we should be using rather than the incantation we are now.

[tseaver]

$ /opt/Python-2.7.13/bin/virtualenv /tmp/pep440
New python executable in /tmp/pep440/bin/python
Installing setuptools, pip, wheel...done.
$ /tmp/pep440/bin/pip install google-cloud-core~=0.24
Collecting google-cloud-core~=0.24
  Using cached google_cloud_core-0.24.1-py2.py3-none-any.whl
...

[dhermes]

LGTM

[dhermes]

I'm not sure we're using it anywhere? Or do you mean rather than the lower-upper bound combination?