Fix gate error "mysqladmin: command not found"

mysqladmin package is required in tools/test-setup.sh
so adding bindep.txt file for this binary dependencies

- http://lists.openstack.org/pipermail/openstack-discuss/2019-June/007272.html

Change-Id: I6e624fe1b99a6257147deb694e0da87590e4102e

bindep.txt

@@ -0,0 +1,10 @@
+# This is a cross-platform list tracking distribution packages needed by tests;
+# see http://docs.openstack.org/infra/bindep/ for additional information.
+
+mysql-client [platform:dpkg]
+mysql-server [platform:dpkg]
+postgresql
+postgresql-client [platform:dpkg]
+postgresql-server [platform:rpm]
+postgresql-devel [platform:rpm]
+postgresql-server-dev-all [platform:dpkg]

tox.ini

@@ -82,3 +82,14 @@ deps = pip_check_reqs
 commands=
     pip-extra-reqs -d --ignore-file=coverage2sql/tests/* coverage2sql
     pip-missing-reqs -d --ignore-file=coverage2sql/tests/* coverage2sql
+
+[testenv:bindep]
+basepython = python3
+# Do not install any requirements. We want this to be fast and work even if
+# system dependencies are missing, since it's used to tell you what system
+# dependencies are missing! This also means that bindep must be installed
+# separately, outside of the requirements files, and develop mode disabled
+# explicitly to avoid unnecessarily installing the checked-out repo too (this
+# further relies on "tox.skipsdist = True" above).
+deps = bindep
+commands = bindep test