Make CloudSigma snapshot tests pending

There appears to be a number of bugs in the CloudSigma mock interface.

The `snapshots` key is `nil` and adding a new snapshot fails. Working
around that, the tests timeout because there is no mechanism to change
the snapshots state from "creating" so it never becomes `available?`

tests/cloudsigma/models/snapshot_tests.rb

@@ -1,4 +1,6 @@
 Shindo.tests('Fog::Compute[:cloudsigma] | snapshot model', ['cloudsigma']) do
+  pending if Fog.mocking?
+
   volume = Fog::Compute[:cloudsigma].volumes.create(:name => 'fogmodeltest', :size => 1024**3, :media => :disk)
   volume.wait_for { available? } unless Fog.mocking?
 

tests/cloudsigma/models/snapshots_tests.rb

@@ -1,4 +1,5 @@
 Shindo.tests('Fog::Compute[:cloudsigma] | snapshots collection', ['cloudsigma']) do
+  pending if Fog.mocking?
 
   volume = Fog::Compute[:cloudsigma].volumes.create(:name => 'fogtest', :size => 1024**3, :media => :disk)
   volume.wait_for { available? } unless Fog.mocking?

tests/cloudsigma/requests/snapshots_tests.rb

@@ -1,4 +1,5 @@
 Shindo.tests('Fog::Compute[:cloudsigma] | snapshot requests', ['cloudsigma']) do
+  pending if Fog.mocking?
 
   @snapshot_format = {
       'uuid' => String,