returnCredentials

import std.process: environment;
assert(is(typeof(returnCredentials()) == Credentials));
assert(is(typeof(returnCredentials().youtubeAPIKey) == string));
assert(is(typeof(returnCredentials().youtubeChannelID) == string));
assert(returnCredentials().youtubeAPIKey == environment.get("YOUTUBE_API_KEY"));
assert(returnCredentials().youtubeChannelID == environment.get("YOUTUBE_CHANNEL_ID"));