Get bucket ARN
Examples
bucket_arn("somebucket")
#> arn:aws:s3:::somebucket
bucket_arn("somebucket", objects = "*")
#> arn:aws:s3:::somebucket/*
bucket_arn("somebucket", objects = "data.csv")
#> arn:aws:s3:::somebucket/data.csv
bucket_arn("somebucket", objects = "myfolder/subset/data.csv")
#> arn:aws:s3:::somebucket/myfolder/subset/data.csv
bucket_arn("somebucket", objects = "myfolder/subset/*")
#> arn:aws:s3:::somebucket/myfolder/subset/*