Move influxdb install into tox.ini and plugin.sh

Influxdb is a database which is better to move into tox.ini
from requirements.txt to make it more dynamic.

Change-Id: I1448ec7fc5585cb3b189c66f0b258c6df4e50d7d

devstack/plugin.sh

@@ -855,6 +855,7 @@ function install_monasca_api_python {
 
     pip_install gunicorn
     pip_install PyMySQL
+    pip_install influxdb==2.8.0
 
     (cd "${MONASCA_BASE}"/monasca-api ; sudo python setup.py sdist)
 
@@ -1068,6 +1069,7 @@ function install_monasca_persister_python {
     PIP_VIRTUAL_ENV=/opt/monasca-persister
 
     pip_install $MONASCA_PERSISTER_SRC_DIST
+    pip_install influxdb==2.8.0
 
     unset PIP_VIRTUAL_ENV
 

requirements.txt

@@ -13,7 +13,7 @@ pbr
 six
 pyparsing
 voluptuous
-influxdb
+#influxdb
 eventlet
 kafka-python>=0.9.5,<1.0.0
 simplejson

tox.ini

@@ -12,6 +12,7 @@ deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 whitelist_externals = find
 commands =
+  pip install influxdb==2.8.0
   find . -type f -name "*.pyc" -delete
   python setup.py testr --testr-args='{posargs}'