OpenStackLrms: do not require that key pair names are alphanumeric.

Allow alphanumeric plus underscore, dash, and dot.  It's
still (likely) more restrictive than the actual OpenStack API (which
documents no limits on the names), but should be OK for most
people to live with.

gc3libs/backends/openstack.py

@@ -165,15 +165,13 @@ def __init__(self, name,
         self.os_password = auth.os_password
         self.os_tenant_name = auth.os_project_name
         self.os_region_name = os_region
-        if self.os_auth_url is None:
-            raise gc3libs.exceptions.InvalidArgument(
-                "Cannot connect to the OpenStack API:"
-                " No 'os_auth_url' argument passed to the OpenStack backend.")
         # Keypair names can only contain alphanumeric chars!
-        if not set(keypair_name).issubset(set(ascii_letters + digits + '_')):
+        if not set(keypair_name).issubset(set(ascii_letters + digits + '_-.')):
             raise ConfigurationError(
-                "Keypair name `%s` is invalid: keypair names can only contain "
-                "alphanumeric chars: [a-zA-Z0-9_]" % keypair_name)
+                "Keypair name `{0}` is invalid:"
+                " keypair names can only consist of"
+                " alphanumeric chars, plus `_`, `-`, and `.`"
+                .format(keypair_name))
         self.keypair_name = keypair_name
         self.public_key = os.path.expanduser(
             os.path.expandvars(public_key.strip()))