add manual tox environment branch

Author: mattsb42-aws

tox.ini

@@ -54,6 +54,7 @@ commands =
     accept: {[testenv:base-command]commands} test/ -m accept
     examples: {[testenv:base-command]commands} examples/test/ -m examples
     all: {[testenv:base-command]commands} test/ examples/test/
+    manual: {[testenv:base-command]commands}
 
 # Verify that local tests work without environment variables present
 [testenv:nocmk]