Set AWS Elasticache Port Number to be required

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

builtin/providers/aws/resource_aws_elasticache_cluster.go

@@ -52,8 +52,7 @@ func resourceAwsElasticacheCluster() *schema.Resource {
 			},
 			"port": &schema.Schema{
 				Type:     schema.TypeInt,
-				Default:  11211,
-				Optional: true,
+				Required: true,
 				ForceNew: true,
 			},
 			"engine_version": &schema.Schema{
@@ -123,7 +122,7 @@ func resourceAwsElasticacheClusterCreate(d *schema.ResourceData, meta interface{
 	numNodes := int64(d.Get("num_cache_nodes").(int)) // 2
 	engine := d.Get("engine").(string)                // memcached
 	engineVersion := d.Get("engine_version").(string) // 1.4.14
-	port := int64(d.Get("port").(int))                // 11211
+	port := int64(d.Get("port").(int))                // e.g) 11211
 	subnetGroupName := d.Get("subnet_group_name").(string)
 	securityNameSet := d.Get("security_group_names").(*schema.Set)
 	securityIdSet := d.Get("security_group_ids").(*schema.Set)

builtin/providers/aws/resource_aws_elasticache_cluster_test.go

@@ -120,6 +120,7 @@ resource "aws_elasticache_cluster" "bar" {
     engine = "memcached"
     node_type = "cache.m1.small"
     num_cache_nodes = 1
+    port = 11211
     parameter_group_name = "default.memcached1.4"
     security_group_names = ["${aws_elasticache_security_group.bar.name}"]
 }