feat: manage master credentials in secrets manager #50

Job	Run time
terraform-module / CI / Labels Validate	2s
terraform-module / Readme	0s
terraform-module / CI / Find modules	3s
terraform-module / CI / Format HCL	20s
terraform-module / CI / Codeowners validate	5s
terraform-module / CI / Lint (.)	12s
terraform-module / CI / Lint (./examples/basic)	20s
terraform-module / CI / Lint (./examples/complete)	22s
terraform-module / CI / Lint (./examples/enhanced_monitoring)	11s
terraform-module / CI / Lint (./examples/postgres)	16s
terraform-module / CI / Lint (./examples/serverless_mysql)	12s
terraform-module / CI / Lint (./examples/serverless_mysql57)	13s
terraform-module / CI / Lint (./examples/serverlessv2_postgres)	12s
terraform-module / CI / Lint (./examples/with_cluster_parameters)	14s
terraform-module / ci	1s
terraform-module / Release	0s
	2m 43s

Provide feedback