Switched to google-resumable-media in BigQuery.

[dhermes]

@jonparrott Asked that I make a "do not merge" PR out of this, as a placeholder for the work remaining in #1998.

When I wrote this code (May 10th), the system tests all passed without issue (THAT WAS NOT TRUE WHEN I WROTE IT), but the unit tests are currently very broken by this change.

I am very much intentionally leaving the "Allow edits from maintainers" box checked, so anyone is free to fix the unit tests 😀

[dhermes]

OK after some work last night by @jonparrott and by me this AM, the unit tests are passing at 100%.

I'm fairly certain there will be a system test breakage though. I seem to recall the getting the size from the final 200 response of a finished resumable upload is "impossible" with the BigQuery API. (The real story: I assumed all APIs would return size because Storage did, it may have been a bad assumption.)

[dhermes]

w00t! I confirmed the system tests pass locally:

$ nox -s "system_tests(python_version='2.7')"
nox > Running session system_tests(python_version='2.7')
nox > virtualenv .../bigquery/.nox/sys-2-7 -p python2.7
nox > chdir .../bigquery
nox > pip install --upgrade mock pytest ../core
nox > pip install --upgrade ../storage ../test_utils
nox > pip install --upgrade .
nox > py.test --quiet tests/system.py
.........................
25 passed in 163.06 seconds
nox > Session system_tests(python_version='2.7') successful. :)
$
$
$ nox -s "system_tests(python_version='3.6')"
nox > Running session system_tests(python_version='3.6')
nox > virtualenv .../bigquery/.nox/sys-3-6 -p python3.6
nox > chdir .../bigquery
nox > pip install --upgrade mock pytest ../core
nox > pip install --upgrade ../storage ../test_utils
nox > pip install --upgrade .
nox > py.test --quiet tests/system.py
.........................
25 passed in 155.69 seconds
nox > Session system_tests(python_version='3.6') successful. :)

[dhermes]

OK CircleCI is green. Let's merge?!?