add tests for temporary token support on EC2NodeDriver
add tests for temporary token support on EC2NodeDriver

Closes #820

Signed-off-by: Tomaz Muraus <bb4af54d4692022d34bcf290dffd91d21e083d18@tomaz.me>

pquentin/libcloud,lochiiconnectivity/libcloud,ByteInternet/libcloud,StackPointCloud/libcloud,techhat/libcloud,mgogoulos/libcloud,mistio/libcloud,mgogoulos/libcloud,wuyuewen/libcloud,apache/libcloud,iPlantCollaborativeOpenSource/libcloud,iPlantCollaborativeOpenSource/libcloud,Kami/libcloud,t-tran/libcloud,illfelder/libcloud,lochiiconnectivity/libcloud,erjohnso/libcloud,watermelo/libcloud,illfelder/libcloud,SecurityCompass/libcloud,Scalr/libcloud,ZuluPro/libcloud,SecurityCompass/libcloud,andrewsomething/libcloud,NexusIS/libcloud,samuelchong/libcloud,samuelchong/libcloud,DimensionDataCBUSydney/libcloud,t-tran/libcloud,pquentin/libcloud,SecurityCompass/libcloud,StackPointCloud/libcloud,DimensionDataCBUSydney/libcloud,samuelchong/libcloud,vongazman/libcloud,t-tran/libcloud,ZuluPro/libcloud,apache/libcloud,wuyuewen/libcloud,mistio/libcloud,pquentin/libcloud,andrewsomething/libcloud,andrewsomething/libcloud,ByteInternet/libcloud,watermelo/libcloud,mistio/libcloud,NexusIS/libcloud,vongazman/libcloud,techhat/libcloud,vongazman/libcloud,ZuluPro/libcloud,Scalr/libcloud,watermelo/libcloud,techhat/libcloud,wuyuewen/libcloud,StackPointCloud/libcloud,erjohnso/libcloud,Kami/libcloud,illfelder/libcloud,DimensionDataCBUSydney/libcloud,mgogoulos/libcloud,apache/libcloud,NexusIS/libcloud,erjohnso/libcloud,lochiiconnectivity/libcloud,Scalr/libcloud,iPlantCollaborativeOpenSource/libcloud,Kami/libcloud,ByteInternet/libcloud