project-config: Merge lint jobs (2/2)

Since both pep8 and bashate are voting, we can merge the two lint
targets into the "common" pep8 lint target. There's no need for a
separate bashate run.

This change is the second part for this.
Since the jobs are changed, we can now remove the obsolete bashate
tox.ini target.

Change-Id: I572ba3fe8b3a9a05f5239a858d2f701bfd8f684d

tox.ini

@@ -63,14 +63,12 @@ commands =
   {toxinidir}/tools/run-layout.sh
   {toxinidir}/tools/layout-checks.py
 
-[testenv:bashate]
-commands = {toxinidir}/tools/run-bashate.sh
-
 [testenv:infra-docs]
 deps =
    Jinja2
    PyYAML
 commands = {toxinidir}/docs-site/generate_infra_index.py {toxinidir}/docs-site/infra-documents.yaml
+
 [testenv:specs]
 deps =
    Jinja2