Add flag to skip tests when pushing a release

hopefully this doesn't get used much, but currently am having a major
headache when running python 3.7 tests via tox.  probably should just
drop support for that one ASAP..

tasks.py

@@ -14,10 +14,11 @@ exec(open(os.path.join(here, 'src', 'wuttjamaican', '_version.py')).read())
 
 
 @task
-def release(c):
+def release(c, skip_tests=False):
     """
     Release a new version of WuttJamaican
     """
+    if not skip_tests:
         c.run('tox')
 
     # rebuild local tar.gz file for distribution