Update registry assets to simple solidity registry implementation

docs/web3.pm.rst

@@ -40,25 +40,17 @@ The following methods are available on the ``web3.pm`` namespace.
 .. autoclass:: web3.pm.PM
    :members:
 
-.. autoclass:: web3.pm.ERCRegistry
+.. autoclass:: web3.pm.ERC1319Registry
    :members: __init__, _release, _get_package_name, _get_all_package_ids, _get_release_id, _get_all_release_ids, _get_release_data, _generate_release_id, _num_package_ids, _num_release_ids
 
-.. autoclass:: web3.pm.VyperReferenceRegistry
-   :members: deploy_new_instance, owner, transfer_owner
-
-.. autoclass:: web3.pm.SolidityReferenceRegistry
-   :members:
-
 
 Creating your own Registry class
 --------------------------------
-If you want to implement your own registry and use it with ``web3.pm``, you must create a subclass that inherits from ``ERCRegistry``, and implements all the `ERC 1319 standard methods <https://github.com/ethereum/EIPs/issues/1319>`_ prefixed with an underscore in ``ERCRegistry``. Then, you have to manually set it as the ``registry`` attribute on ``web3.pm``.
+If you want to implement your own registry and use it with ``web3.pm``, you must create a subclass that inherits from ``ERC1319Registry``, and implements all the `ERC 1319 standard methods <https://github.com/ethereum/EIPs/issues/1319>`_ prefixed with an underscore in ``ERC1319Registry``. Then, you have to manually set it as the ``registry`` attribute on ``web3.pm``.
 
 .. code-block:: python
     
     custom_registry = CustomRegistryClass(address, w3)
     w3.pm.registry = custom_registry
 
-One reason a user might want to create their own Registry class is if they build a custom Package Registry smart contract that has features beyond those specified in `ERC 1319 <https://github.com/ethereum/EIPs/issues/1319>`_. For example, the ability to delete a release or some micropayment feature. Rather than accessing those functions directly on the contract instance, they can create a custom ``ERCRegistry`` subclass to easily call both the standard & custom methods.
-
-The ``VyperReferenceRegistry`` class is an example of this, as it contains all of the ``ERC 1319`` defined functions (prefixed with an underscore, eg ``_get_package_name``) but also contains functions that are unique to the Vyper Registry reference implementation (eg ``transfer_owner``).
+One reason a user might want to create their own Registry class is if they build a custom Package Registry smart contract that has features beyond those specified in `ERC 1319 <https://github.com/ethereum/EIPs/issues/1319>`_. For example, the ability to delete a release or some micropayment feature. Rather than accessing those functions directly on the contract instance, they can create a custom ``ERC1319Registry`` subclass to easily call both the standard & custom methods.

ethpm/assets/simple-registry/contracts/Ownable.sol

@@ -0,0 +1,63 @@
+pragma solidity ^0.5.0;
+
+/**
+ * @dev Contract module which provides a basic access control mechanism, where
+ * there is an account (an owner) that can be granted exclusive access to
+ * specific functions.
+ *
+ * This module is used through inheritance. It will make available the modifier
+ * `onlyOwner`, which can be applied to your functions to restrict their use to
+ * the owner.
+ */
+contract Ownable {
+    address private _owner;
+
+    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
+
+    /**
+     * @dev Initializes the contract setting the deployer as the initial owner.
+     */
+    constructor () internal {
+        _owner = msg.sender;
+        emit OwnershipTransferred(address(0), _owner);
+    }
+
+    /**
+     * @dev Returns the address of the current owner.
+     */
+    function owner() public view returns (address) {
+        return _owner;
+    }
+
+    /**
+     * @dev Throws if called by any account other than the owner.
+     */
+    modifier onlyOwner() {
+        require(isOwner(), "Ownable: caller is not the owner");
+        _;
+    }
+
+    /**
+     * @dev Returns true if the caller is the current owner.
+     */
+    function isOwner() public view returns (bool) {
+        return msg.sender == _owner;
+    }
+
+    /**
+     * @dev Transfers ownership of the contract to a new account (`newOwner`).
+     * Can only be called by the current owner.
+     */
+    function transferOwnership(address newOwner) public onlyOwner {
+        _transferOwnership(newOwner);
+    }
+
+    /**
+     * @dev Transfers ownership of the contract to a new account (`newOwner`).
+     */
+    function _transferOwnership(address newOwner) internal {
+        require(newOwner != address(0), "Ownable: new owner is the zero address");
+        emit OwnershipTransferred(_owner, newOwner);
+        _owner = newOwner;
+    }
+}