chore: release notes for v0.18.x (#155)

Also update ``INSTALL_GOOGLE_CLOUD_CPP_COMMON_FROM_SOURCE`` rules, and
``google_cloud_cpp_common`` and ``google_cloud_cpp_grpc_utils`` ABI dumps.

Author: devbww

CHANGELOG.md

@@ -1,6 +1,23 @@
 # Changelog
 
-## v0.18.x - TBD
+## v0.19.x - TBD
+
+## v0.18.x - 2020-02
+
+**BREAKING CHANGES:**
+* feat!: change the result type for timers to StatusOr (#134)
+  `CompletionQueue::MakeRelativeTimer` and `CompletionQueue::MakeDeadlineTimer()`
+  now return a `future<StatusOr<std::chrono::system_clock::time_point>>`.
+  This change is needed because now these operations may fail if the completion
+  queue is shutdown before the timer is set.
+* chore: remove `CompletionQueue` parameter to `AsyncGrpcOperation::Notify` (#136)
+
+**Other Changes:**
+* fix: google/cloud/grpc_utils/examples does not exist (#149)
+* feat: gracefully fail adding to the `CompletionQueue` after `Shutdown` (#138)
+* fix: remove the redundant conditions in the `Run()` loop (#131)
+* fix: crashes with non-empty CompletionQueue shutdown (#127)
+* chore: move release notes to CHANGELOG.md (#128)
 
 ## v0.17.x - 2019-12
 

ci/templates/kokoro/docker-fragments.sh

@@ -112,9 +112,9 @@ _EOF_
 
 read_into_variable INSTALL_GOOGLE_CLOUD_CPP_COMMON_FROM_SOURCE <<'_EOF_'
 WORKDIR /var/tmp/build
-RUN wget -q https://github.com/googleapis/google-cloud-cpp-common/archive/v0.16.0.tar.gz && \
-    tar -xf v0.16.0.tar.gz && \
-    cd google-cloud-cpp-common-0.16.0 && \
+RUN wget -q https://github.com/googleapis/google-cloud-cpp-common/archive/v0.18.0.tar.gz && \
+    tar -xf v0.18.0.tar.gz && \
+    cd google-cloud-cpp-common-0.18.0 && \
     cmake -H. -Bcmake-out \
         -DBUILD_TESTING=OFF \
         -DGOOGLE_CLOUD_CPP_TESTING_UTIL_ENABLE_INSTALL=ON && \