* Making IERC721Receiver an interface

* Update IERC721Receiver.sol

Co-authored-by: Nicolás Venturo <nicolas.venturo@gmail.com>
(cherry picked from commit 78dc3773)

* remove ethpm.json

* update releasing document

* fix release documentation to be more realistic

* Add baseURI to ERC721MinterPauser constructor

* Add tokenURI to mint

* Remove tokenId and tokenURI from ERC721 deploy ready

* Rename ERC721MinterPauser to ERC721MinterAutoID, remove Pausable mechanisms

* Restore pausing to ERC721

* Rename deploy ready to presets

* Rename ERC721 preset

* Improve Hooks docs

* Improve Utils docs

* Apply suggestions from code review

Co-Authored-By: Francisco Giordano <frangio.1@gmail.com>

* Add enumerable code samples

* Remove import statement from example

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

Bumps [acorn](https://github.com/acornjs/acorn) from 6.4.0 to 6.4.1. **This update includes security fixes.**
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](https://github.com/acornjs/acorn/compare/6.4.0...6.4.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Bumps [solhint](https://github.com/protofire/solhint) from 3.0.0-rc.7 to 3.0.0-rc.8.
- [Release notes](https://github.com/protofire/solhint/releases)
- [Changelog](https://github.com/protofire/solhint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/protofire/solhint/compare/v3.0.0-rc.7...v3.0.0-rc.8)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Bumps [@openzeppelin/test-environment](https://github.com/OpenZeppelin/openzeppelin-test-environment) from 0.1.3 to 0.1.4.
- [Release notes](https://github.com/OpenZeppelin/openzeppelin-test-environment/releases)
- [Changelog](https://github.com/OpenZeppelin/openzeppelin-test-environment/blob/master/CHANGELOG.md)
- [Commits](https://github.com/OpenZeppelin/openzeppelin-test-environment/compare/v0.1.3...v0.1.4)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Bumps [@openzeppelin/cli](https://github.com/OpenZeppelin/openzeppelin-sdk) from 2.8.1 to 2.8.2.
- [Release notes](https://github.com/OpenZeppelin/openzeppelin-sdk/releases)
- [Commits](https://github.com/OpenZeppelin/openzeppelin-sdk/compare/v2.8.1...v2.8.2)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

* Remove isConstructor requirement from _setupRole

* Remove isConstructor requirement from _setupDecimals

* Update contracts/access/AccessControl.sol

Co-Authored-By: Francisco Giordano <frangio.1@gmail.com>

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

* Fix deprecation warnings

* Workaround linter bug

* rename Strings.fromUint256 to Strings.toString

* add changelog entry

* fix conflict with js toString method

* Improve ERC20/721 Pausable docs

* Add ERC20Pausable mint and burn tests

* Add ERC721Pausable mint and burn tests

* Add _beforeTransfer hook in ERC777 to mint and burn

* provide 'automatic' token URI by appending the token ID to the base URI, if a base is set but no token-specific URI is available

* make the three cases more explicit, avoid else after return

* adjust comments to reflect reality

Co-authored-by: Nicolás Venturo <nicolas.venturo@gmail.com>

Bumps [@openzeppelin/cli](https://github.com/OpenZeppelin/openzeppelin-sdk) from 2.8.0 to 2.8.1.
- [Release notes](https://github.com/OpenZeppelin/openzeppelin-sdk/releases)
- [Commits](https://github.com/OpenZeppelin/openzeppelin-sdk/compare/v2.8.0...v2.8.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Bumps [solhint](https://github.com/protofire/solhint) from 3.0.0-rc.6 to 3.0.0-rc.7.
- [Release notes](https://github.com/protofire/solhint/releases)
- [Changelog](https://github.com/protofire/solhint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/protofire/solhint/compare/v3.0.0-rc.6...v3.0.0-rc.7)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

* Update access-control.adoc to make compile

Add call to `ERC20("MyToken", "TKN")` in `MyToken` constructor

* Update access-control.adoc to make compile

Add call to `ERC20("MyToken", "TKN")` in `MyToken` constructor

* Update access-control.adoc MyToken formatting

* Update erc20-supply.adoc to make compile

Add call to `ERC20("MyToken", "TKN")` in `ERC20FixedSupply` constructor

* Update erc20-supply.adoc to make compile

Add constructor to `ERC20WithMinerReward`

* Update erc20-supply.adoc to make compile

In `MinerRewardMinter` use `ERC20MinterPauser`

* Update erc20-supply.adoc to make compile

Add constructor and override to `ERC20WithAutoMinerReward`

* Update erc777.adoc to make compile

* Update gsn-strategies.adoc to make compile

* Update gsn-strategies.adoc to make compile

Fix imports, add overrides, and revert reason to `MyContract`

Co-authored-by: Nicolás Venturo <nicolas.venturo@gmail.com>