Avoid tox_install.sh for constraints support

We do not need tox_install.sh, pip can handle constraints itself
and install the project correctly. Thus update tox.ini and remove
the now obsolete tools/tox_install.sh file.

This follows https://review.openstack.org/#/c/508061 to remove
tools/tox_install.sh.

Change-Id: I42b7dcd3e9e41688ac3bd8b9c9fb9b39f90c3e9a
diff --git a/tools/tox_install.sh b/tools/tox_install.sh
deleted file mode 100755
index e61b63a..0000000
--- a/tools/tox_install.sh
+++ /dev/null
@@ -1,30 +0,0 @@
-#!/usr/bin/env bash
-
-# Client constraint file contains this client version pin that is in conflict
-# with installing the client from source. We should remove the version pin in
-# the constraints file before applying it for from-source installation.
-
-CONSTRAINTS_FILE="$1"
-shift 1
-
-set -e
-
-# NOTE(tonyb): Place this in the tox enviroment's log dir so it will get
-# published to logs.openstack.org for easy debugging.
-localfile="$VIRTUAL_ENV/log/upper-constraints.txt"
-
-if [[ "$CONSTRAINTS_FILE" != http* ]]; then
-    CONSTRAINTS_FILE="file://$CONSTRAINTS_FILE"
-fi
-# NOTE(tonyb): need to add curl to bindep.txt if the project supports bindep
-curl "$CONSTRAINTS_FILE" --insecure --progress-bar --output "$localfile"
-
-pip install -c"$localfile" openstack-requirements
-
-# This is the main purpose of the script: Allow local installation of
-# the current repo. It is listed in constraints file and thus any
-# install will be constrained and we need to unconstrain it.
-edit-constraints "$localfile" -- "$CLIENT_NAME"
-
-pip install -c"$localfile" -U "$@"
-exit $?
diff --git a/tox.ini b/tox.ini
index 196d873..3163c7d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,13 +5,13 @@
 
 [testenv]
 usedevelop = True
-install_command = {toxinidir}/tools/tox_install.sh {env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
-deps = -r{toxinidir}/requirements.txt
+install_command = pip install {opts} {packages}
+deps =
+       -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
+       -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 setenv =
     VIRTUAL_ENV={envdir}
-    BRANCH_NAME=master
-    CLIENT_NAME=designate-tempest-plugin
   PYTHONDONTWRITEBYTECODE=1
 whitelist_externals = sh
                       find