Cut 0.15.0 release.

[dhermes]

/cc @waprin

---

$ git log -1 --pretty=%H
b27907be562e81a10abe258ee32d039146e65768
$ git log 0.14.0..HEAD | grep 'Merge pull request ' |  awk -F ' ' '{print $4}' | sort

yields
#1772
#1787
#1802
#1804
#1805
#1808
#1810
#1820
#1823
#1825
#1831
#1834

[dhermes]

Translate

• Add basic implementation of the Translate API (Basic implementation of Translate API. #1772)

Datastore

• Ensure that limit is reduced correctly in paging queries (Reducing limit over the life of a datastore query iterator. #1787)

Logging

• Remove project ID validation when unmarshalling log entries (Don't enforce project ID validation when unmarshallig log entries #1808)
• Remove metric and sink name validation. (Fix 'Sink.from_api_repr'. #1825)
• WIP toward supporting Pubsub-over-gRPC using GAX (side-by-side with JSON-over-HTTP) (Factor API-related calls into service-specific helpers. #1820, Repair logging client 'list_*' methods. #1823)

Bigtable

• Make the Client context manager return a valid context manager on entry (Return self in Bigtable client __enter__. #1810)

BigQuery

• Add support for "dry run" for queries (Dry Run for bigquery queries #1834)

---

Admin type PRs not in release: #1802, #1804, #1805, #1831

[tseaver]

LGTM

[dhermes]

FYI @waprin you are all good to update the docs you were working on in #1807