chore: Prepare for 2.0 release

[plamut]

This PR should serve as a preview of the 2.0 release.

For a start, the BQ Storage v1beta1 compatibility code is removed, as it will not be needed anymore once BQ Storage v2.0.0 is released.

TODO list:

• Fix import paths in tests and samples that are affected by bigquery_v2 changes.
• Describe bigquery_v2 changes in UPGRADING guide.
• Fix docs, include bigquery_v2 in them, if necessary.

[plamut]

BQ Storage 2.0.0 released, re-running.

[plamut]

FWIW, the snippets tests in samples/snippets fail because the generated noxfile tries to install BigQuery v1.x, but the snippets require v2.0.0 that is still in the making. They pass locally if INSTALL_LIBRARY_FROM_SOURCE env variable is set and the following patch is applied:

diff --git samples/snippets/noxfile.py samples/snippets/noxfile.py
index 5660f08..66589f5 100644
--- samples/snippets/noxfile.py
+++ samples/snippets/noxfile.py
@@ -158,14 +158,17 @@ def _session_tests(session, post_install=None):
         session.install("-r", "requirements-test.txt")
 
     if INSTALL_LIBRARY_FROM_SOURCE:
-        session.install("-e", _get_repo_root())
+        session.install("-e", _get_repo_root() + "[all]")
 
     if post_install:
         post_install(session)
 
diff --git samples/snippets/requirements.txt samples/snippets/requirements.txt
index 7fe8391..4753c47 100644
--- samples/snippets/requirements.txt
+++ samples/snippets/requirements.txt
@@ -1,4 +1,4 @@
-google-cloud-bigquery[pandas,bqstorage,pyarrow]==1.26.1
+# google-cloud-bigquery[pandas,bqstorage,pyarrow]==1.26.1
 google-auth-oauthlib==0.4.1
 ipython==7.16.1; python_version < '3.7'
 ipython==7.17.0; python_version >= '3.7'

[tswast]

They pass locally if INSTALL_LIBRARY_FROM_SOURCE env variable is set and the following patch is applied:

Do we need to add the necessary extras to requirements.txt?

[tswast]

Since it looks like requirements.txt is used to install packages, even when INSTALL_LIBRARY_FROM_SOURCE is set, I'm a bit confused as to why pandas isn't getting installed.

python-bigquery/samples/snippets/noxfile.py

Line 155 in fbbe0cb

session.install("-r", "requirements.txt")

Maybe I missed some logic that filters out google-cloud-bigquery[pandas,...] from that installation?

[plamut]

@tswast Ah, I think that's probably because I temporarily commented out the google-cloud-python line from requirements.txt completely, I just wanted to test with a local version of the library.

(and then had to adjust the installation from source line in noxfile to actually get all those extras installed)

[crwilcox]

Hammer merging to work around sample tests.

[plamut]

@crwilcox Thanks!

Release PR (#284) will probably need the same hammer love.