FileSystem settings in newFileSystem

[stefanofornari]

AS A user
I WANT to easily configure a new file system with FileSystems.newFileSystem("s3://...", env)
SO THAT each instance can have its own environment

NOTES

1. it could be something like

FileSystems.newFileSystem(myuri, new S3NioSpiConfiguration()
    .withAccessKey("access-key")
    .withSecretKey("secret-key")
    .withEndpointProtocol("http")
);

[stefanofornari]

closing as duplicate of #61