Set Elasticache Port number to not be set by default, and require
Elasticache Port number to be specified.
Also updated acceptance tests to supply port number upon resource
declaration
Fixes#2084
- rename test to have _basic suffix, so we can run it individually
- use us-east-1 for basic test, since that's probably the only region that has
Classic
- update the indexing of nodes; cache nodes are 4 digits
Needs to wait for len(cluster.CacheNodes) == cluster.NumCacheNodes, since
apparently that takes a bit of time and the initial response always has
an empty collection of nodes