chore: use nox and release-please; drop 3.4 (#852)



Co-authored-by: Kamil BreguĊ‚a <mik-laj@users.noreply.github.com>
Co-authored-by: Christopher Wilcox <crwilcox@google.com>
diff --git a/.kokoro/build.sh b/.kokoro/build.sh
index e0c966b..ab8cebb 100755
--- a/.kokoro/build.sh
+++ b/.kokoro/build.sh
@@ -1,4 +1,17 @@
 #!/bin/bash
+# Copyright 2018 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 set -eo pipefail
 
@@ -7,7 +20,20 @@
 # Disable buffering, so that the logs stream through.
 export PYTHONUNBUFFERED=1
 
-python3 -m pip install --upgrade tox
+# Debug: show build environment
+env | grep KOKORO
 
-# Run tests
-tox
+# Setup service account credentials.
+export GOOGLE_APPLICATION_CREDENTIALS=${KOKORO_GFILE_DIR}/service-account.json
+
+# Setup project id.
+export PROJECT_ID=$(cat "${KOKORO_GFILE_DIR}/project-id.json")
+
+# Remove old nox
+python3.6 -m pip uninstall --yes --quiet nox-automation
+
+# Install nox
+python3.6 -m pip install --upgrade --quiet nox
+python3.6 -m nox --version
+
+python3.6 -m nox