Add support to the history import tools for release-type

When trying to use the history import tools we need to use the correct
release-type setting to validate tags.

We can't use versionutils.validate_version() as it's a generator which is
hard to use in a sorted() function.  Insetad introduce
versionutils.canonical_version() which will return the version is valid
or raise a ValueError() exception.

Change-Id: If10aab4c573342227e2909fd84f843c96f3abc43

openstack_releases/versionutils.py

@@ -56,3 +56,11 @@ def validate_version(versionstr, release_type='std'):
         if canonical != versionstr:
             yield 'Version %r does not match canonical form %r' % \
                 (versionstr, canonical)
+
+
+def canonical_version(versionstr, release_type='std'):
+    """Given a version string verify it is in the canonical form."""
+    errors = list(validate_version(versionstr, release_type))
+    if errors:
+        raise ValueError(errors[-1])
+    return versionstr