Migrate official aragon apps to Buidler set up

[eternauta1337]

• Fix Migrate voting to Buidler aragon-cli#1485 (voting)
• Fix Migrate token-manager to Buidler aragon-cli#1448 (token-manager)
• WIP Fix Migrate vault to Buidler aragon-cli#1509 (vault)
  • Failing test: set up the default vault correctly to recover ETH from the kernel - ALSO FAILS ON MASTER
• WIP Fix Migrate agent to Buidler aragon-cli#1484 (agent)
  • Also runs vault tests, and as stated above, one of them fails - ALSO FAILS ON MASTER
• WIP Fix Migrate finance to Buidler aragon-cli#1483 (finance)
  • Two tests failing:
    • "can recover ETH using AragonApp#transferToVault" - ALSO FAILS ON MASTER
    • "fails when too many period transitions are needed"
      • fails, unless gas is set to 3e6 (ten times as much!)
      • passes in master with 3e5 gas, even if ganache-cli.sh is modified to use istanbul
      • Buidler currently has an issue where the fork cannot be modified (reported, fix soon)
      • Also fails when running npx buidler test --network localhost with a running ganache-cli instance with any fork.

== Migration cheatsheet ==

• Grab a boilerplate copy from one of the already ported apps (buidler-apps/voting), and place it in buidler-apps/new_app/. The first boilerplate was obtained from aragon-buidler-boilerplate using create-aragon-app.
• Make sure node_modules is not copied from the previous step. If present, delete it.
• Merge original package.json and new package.json.
• Npm i
• Copy original_app/arapp.json's roles and path to new_app/arapp.json.
• Copy original_app/manifest.json entirely to new_app/manifest.json.
• Delete new_app/app/ and replace it with original_app/app/.
• Replace new_app/app/package.json scripts with those from one of the already ported apps (buidler-apps/voting/app/package.json).
• Replace new_app/contracts/ with original_app/contracts/.
• Replace new_app/contracts/test/TestImports.sol with the one from one of the already ported apps (buidler-apps/voting/contracts/test/TestImports.sol).
• Comment out new_app/buidler.config.js aragon.hooks.
• Run npm start until no dependency errors exist.
  • Dependencies might be missing. Go ahead and install them in new_app/. Copy dependencies from the original_app/package.json and paste them in new_app/package.json in the appropriate place.
  • As soon as you get to a runtime error, continue to the next step.
• Uncomment new_app/buidler.config.js aragon.hooks, and properly implement new_app/scripts/buidler-hooks.js according to the specific deployment setup of the app. Hint: looking at how things are set up in original_app/test/* makes it pretty straight forward.
• Test UI.
• Delete contents of new_app/test/, and replace with original_app/test/.
• Run npm test, porting them from Web3 0.20.x to 1.0.x.
  • Fix errors until all tests pass.
• Push!
• Update this PR description with the issue/fix number.

[eternauta1337]

Closing this PR in favor of #1092, which directly modifies the original app folders.