(Feature) add a script to generate flat source codes, ABI and binaries of Proxies smart-contracts

[vbaranov]

Child of #1035

Problem: metadata of Proxies is stored in ./public/contracts/ and it is static. The idea is to generate these metadata files from the source code at every Wizard deployment.

Solution: add a script, that will get flat source codes, ABI and binaries of Proxies smart-contracts (both: Dutch Auction and Minted capped crowdsale).

From my perspective: A script should have a config. This config should have a parameter to store a hash of commit in https://github.com/poanetwork/auth-os-applications repository (note: this repo is already used in git submodules). A script will start before deployment of Wizard and will:

• get the source code of Minted caped proxy and Dutch Proxy
  • generate flat source of proxies. Example of flattener could be gotten here: https://github.com/poanetwork/auth-os-applications/blob/master/TokenWizard/crowdsale/MintedCappedCrowdsale/scripts/flatten.sh
  • save proxies source codes to ./public/contracts/ folder, into MintedCappedProxy.sol and DutchProxy.sol files
  • compile smart-contracts with Truffle truffle compile and save ABI and binary code to ./public/contracts/ folder into MintedCappedProxy.bin, MintedCappedProxy.abi and DutchProxy.bin, DutchProxy.abi correspondingly