Added support for UpdateShardCound & DescribeLimits

[indieisaconcept]

This change adds support for UpdateShardCount & DescribeLimits.

• UpdateShardCound
• DescribeLimits

Notable Additions

util.createShards
The creation of shards is now a separate utility function as there was an overlap between creating a streams initial shards and adding further via UpdateShardCound.

./test/helpers
When creating an instance of kinesalite for testing, helpers.shardLimit was not passed as an option. This PR also address this.

.editorconfig
Added for future contributors convenience.

[indieisaconcept]

Closing due to discovery of issue with UpdateShardCount

[Druotic]

Hey @indieisaconcept, could you provide some more context around the issue that you found with UpdateShardCount? I may take a stab at picking this back up, as it would enable Terraform provisioning of Kinesis streams (via localstack, which uses this project). (#61) Any context from your previous attempt to help save me some time would be appreciated.

[indieisaconcept]

@Druotic in all honesty I cannot recall. It was possibly because I discovered the time-based restrictions imposed with UpdateShardCount & was intending on adding that functionality for completeness.