vcsa: bump to 6.7.0a release
vcsa: bump to 6.7.0a release

dougm/govmomi,vmware/govmomi,dougm/govmomi,vmware/govmomi,vmware/govmomi,bruceadowns/govmomi,bruceadowns/govmomi,dougm/govmomi,bruceadowns/govmomi