Update transitive dependencies

Created by: Tirokk

Authored by roschaefer Aug 22, 2019 Merged Aug 23, 2019

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I see a security vulnerability warning on Github. I hope that updating transitive dependencies will silence the security warning.

I did rm yarn.lock followed by yarn install.

EDIT: OK, I found out what's causing the security warning. Running

yarn list lodash
├─ bitcore-lib@0.13.19
│  └─ lodash@3.10.1
└─ lodash@4.17.15

gives us the hint that the outdated lodash comes from bitcore-lib which in turn is required by the extremely outdated activitystrea.ms package. I tried to update it's dependencies in my fork without success. If we ever touch the activity pub implementation we might have to maintain this package ourselves.

FYI: @Mastercuber