Stop configuring install_command in tox and stop use pip.

Currently, we are overriding 'install_command' to use 'pip'. This is
considered poor behavior and 'python -m pip' should be used instead:

https://snarky.ca/why-you-should-use-python-m-pip/

It turns out that this is the the default value provided by tox:

https://tox.readthedocs.io/en/latest/config.html#conf-install_command

So we can remove the line and simply use the default value. Use the
right way when it's necessary.

Change-Id: I410173d5fdcd8c592d98eed2f48b98e06299e8b3

Author: damani42

lower-constraints.txt

@@ -38,7 +38,7 @@ jmespath==0.9.0
 jsonpatch==1.16
 jsonpointer==1.13
 jsonschema==2.6.0
-keystoneauth1==3.6.2
+keystoneauth1==3.14.0
 kombu==4.0.0
 linecache2==1.0.0
 MarkupSafe==1.0

requirements.txt

@@ -6,7 +6,7 @@ six>=1.10.0 # MIT
 
 Babel!=2.4.0,>=2.3.4 # BSD
 cliff!=2.9.0,>=2.8.0 # Apache-2.0
-keystoneauth1>=3.6.2 # Apache-2.0
+keystoneauth1>=3.14.0 # Apache-2.0
 openstacksdk>=0.17.0 # Apache-2.0
 osc-lib>=2.0.0 # Apache-2.0
 oslo.i18n>=3.15.3 # Apache-2.0

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-minversion = 3.1
+minversion = 3.2.0
 envlist = py37,pep8
 skipdist = True
 # Automatic envs (pyXX) will only use the python version appropriate to that
@@ -10,9 +10,7 @@ ignore_basepython_conflict = True
 [testenv]
 usedevelop = True
 basepython = python3
-install_command = pip install {opts} {packages}
-setenv = VIRTUAL_ENV={envdir}
-         OS_STDOUT_CAPTURE=1
+setenv = OS_STDOUT_CAPTURE=1
          OS_STDERR_CAPTURE=1
          OS_TEST_TIMEOUT=60
 deps =
@@ -24,6 +22,7 @@ whitelist_externals = stestr
 
 [testenv:fast8]
 # Use same environment directory as pep8 env to save space and install time
+setenv = VIRTUAL_ENV={envdir}
 envdir = {toxworkdir}/pep8
 commands =
   {toxinidir}/tools/fast8.sh
@@ -62,12 +61,12 @@ commands =
 
 [testenv:unit-tips]
 commands =
-    pip install -q -U -e "git+file://{toxinidir}/../cliff#egg=cliff"
-    pip install -q -U -e "git+file://{toxinidir}/../keystoneauth#egg=keystoneauth"
-    pip install -q -U -e "git+file://{toxinidir}/../osc-lib#egg=osc_lib"
-    pip install -q -U -e "git+file://{toxinidir}/../os-client-config#egg=os_client_config"
-    pip install -q -e "git+file://{toxinidir}/../openstacksdk#egg=openstacksdk"
-    pip freeze
+    python -m pip install -q -U -e "git+file://{toxinidir}/../cliff#egg=cliff"
+    python -m pip install -q -U -e "git+file://{toxinidir}/../keystoneauth#egg=keystoneauth"
+    python -m pip install -q -U -e "git+file://{toxinidir}/../osc-lib#egg=osc_lib"
+    python -m pip install -q -U -e "git+file://{toxinidir}/../os-client-config#egg=os_client_config"
+    pythom -m pip install -q -e "git+file://{toxinidir}/../openstacksdk#egg=openstacksdk"
+    python -m pip freeze
     stestr run {posargs}
 whitelist_externals = stestr
 
@@ -81,12 +80,12 @@ commands =
 setenv = OS_TEST_PATH=./openstackclient/tests/functional
 passenv = OS_*
 commands =
-    pip install -q -U -e "git+file://{toxinidir}/../cliff#egg=cliff"
-    pip install -q -U -e "git+file://{toxinidir}/../keystoneauth#egg=keystoneauth"
-    pip install -q -U -e "git+file://{toxinidir}/../osc-lib#egg=osc_lib"
-    pip install -q -U -e "git+file://{toxinidir}/../os-client-config#egg=os_client_config"
-    pip install -q -U -e "git+file://{toxinidir}/../openstacksdk#egg=openstacksdk"
-    pip freeze
+    python -m pip install -q -U -e "git+file://{toxinidir}/../cliff#egg=cliff"
+    python -m pip install -q -U -e "git+file://{toxinidir}/../keystoneauth#egg=keystoneauth"
+    python -m pip install -q -U -e "git+file://{toxinidir}/../osc-lib#egg=osc_lib"
+    python -m pip install -q -U -e "git+file://{toxinidir}/../os-client-config#egg=os_client_config"
+    python -m pip install -q -U -e "git+file://{toxinidir}/../openstacksdk#egg=openstacksdk"
+    python -m pip freeze
     stestr run {posargs}
 
 [testenv:venv]