fix test install

tox.ini

@@ -5,8 +5,8 @@ skipsdist = true
 [testenv]
 passenv = TOXENV
 commands =
-    py{36,37,38,39}: pip install -e '.[dev,sqlite,redis]'
-    py{37,38,39}-uvloop: pip install -e '.[dev,sqlite,redis,uvloop]'
+    py{37,38,39}: pip install -e '.[dev,sqlite,redis,postgres]'
+    py{37,38,39}-uvloop: pip install -e '.[dev,sqlite,redis,postgres,uvloop]'
     pytest .
 
 [testenv:lint]
@@ -19,6 +19,6 @@ commands =
 passenv = TOXENV
 basepython = python3.9
 commands =
-    pip install -e ".[dev,sqlite,redis]"
+    pip install -e ".[dev,sqlite,redis,postgres]"
     pytest --cov . --cov-append --cov-report= .
     coverage report --fail-under=97 --include="postfix_mta_sts_resolver/*" --show-missing