Fix tox deps inheritance

Author: etingof

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 3.4.0
-envlist = {py27, py35, py36, py37, py38}-{unittest}, cover, bandit, build
+envlist = {py27, py35, py36, py37, py38}-{unittest}, conver, bandit, build
 isolated_build = true
 skip_missing_interpreters = true
 
@@ -15,6 +15,7 @@ install_command =
 
 [testenv:unittest]
 deps =
+    {[testenv]deps}
     discover
     -r{toxinidir}/requirements.txt
 commands =
@@ -46,6 +47,7 @@ setenv =
     {[testenv]setenv}
     PYTHON=coverage run --parallel-mode
 deps =
+    {[testenv:unittest]deps}
     coverage
     discover
 commands = coverage erase