installing c snappy library before callign tests

Author: Azfaar Qureshi

Diff for: tox.ini

@@ -135,6 +135,7 @@ envlist =
     pypy3-test-instrumentation-tornado
 
     lint
+    sudo apt-get install libsnappy-dev
     docker-tests
 
 [testenv]
@@ -296,7 +297,6 @@ commands =
   python scripts/eachdist.py lint --check-only
 
 [testenv:docker-tests]
-commands_pre = sudo apt-get install libsnappy-dev
 deps =
   pytest
   asyncpg==0.20.1