Merge pull request #3140 from nymtech/feature/mock-nym-api

ts-packages/mock-nym-api/.env

ts-packages/mock-nym-api/Caddyfile

ts-packages/mock-nym-api/README.md

ts-packages/mock-nym-api/mocks/custom-gateway.json

ts-packages/mock-nym-api/mocks/gateways.json

ts-packages/mock-nym-api/mocks/mixnodes.json

ts-packages/mock-nym-api/package.json

ts-packages/mock-nym-api/src/index.ts

ts-packages/mock-nym-api/tsconfig.json

yarn.lock