Fix for inactive ecs clusters (gruntwork-io#146)

* using random regions for ecscluster tests

* adding filtering for  or  clusters

* adding consistent names for test ECS clusters created

* reverting accidental rename of test

* updating log message

* handling errors in test for random reagion function

* fixing comment meaning

* removing  state after not being able to prove it allows ECS clusters to be tagged

* using fargate supported regions for test

* splitting describeEcsClusters into a separate method & using batches

* optimising describe ECS clusters functionality - removed  operator

* adding comments to filtering logic & extracting out the batch size magic number into a const with comment

Merge pull request gruntwork-io#141 from gruntwork-io/pull-request-123

Add to cloud-nuke the ability to delete ECS clusters with/out "older-than" filtering.

Merge pull request gruntwork-io#135 from gruntwork-io/yori-memeff-s3

Memory efficient s3 delete

Merge pull request gruntwork-io#113 from rhoboat/matching-s3-108

Add config file options for matching s3 bucket names by regex

Merge pull request gruntwork-io#115 from gruntwork-io/pull-request-91

Extend gruntwork-io#91

Merge pull request gruntwork-io#105 from saurabh-hirani/s3-concurrent…

…-get

Adding support for --log-level and concurrent S3 get

Merge pull request gruntwork-io#101 from gruntwork-io/pull-request-96

Prepare gruntwork-io#96 for merge

Merge pull request gruntwork-io#100 from gruntwork-io/yori-fix-panic

Fix source of panic in RDS module

Merge pull request gruntwork-io#97 from gruntwork-io/yori-fix-panic

Fix source of panic in tests

Merge pull request gruntwork-io#94 from gruntwork-io/delete-rds-cluster

Add feature to delete RDS Clusters