add tests for various actions

actions/testdata/regex.workflow

@@ -0,0 +1,9 @@
+workflow "New workflow" {
+  on = "push"
+  resolves = ["filter-version-before-deploy"]
+}
+
+action "filter-version-before-deploy" {
+  uses = "actions/bin/filter@master"
+  args = "tag z?[0-9]+\\.[0-9]+\\.[0-9]+"
+}