Connecting to LND by supplying raw certs and macaroons

[torkelrogstad]

Feature request

Add ability to supply raw certs and macaroons as []byte, instead of specifying a path.

Motivation

When working with nodes and services running in containers, we do not necessarily have (easy) access to the underlying file system used by a container. Instead, it is easier to read specific files (certs and macaroons) out of the container. Being able to supply these would simplify my work flow.

[jalavosus]

#35

[guggero]

Implemented by #51.