to convert mnemonics to private keys:
1. install nodejs
2. install dependencies
3. run command
tested with node version: v8.11.3 get it from https://nodejs.org/en/download/
git clone https://github.com/Switcheo/mnemonic-to-private-key
cd mnemonic-to-private-key
npm install
MNEMONIC='first second third forth fifth sixth seventh eighth ninth tenth eleventh twelfth' node .