ContractFactory classes do not retain their names.

migrated from: https://github.com/pipermerriam/web3.py/issues/172

### What was wrong?

Currently the contract object does not know its own name (the contract name in the source code).

```
contract.__class__.__name__
'PopulusContract'
```

#### Cute Animal Picture

```
(__)
(__) [@@] ? (__) ? (__)
(oo) <=|^^|=> ? (oo) ? |\/|(oo)
/-------VV /--------- \/ /-------\/ /--| \--\/
/ | || / | || / | || / | ||
* ||----|| / | || * ||----|| * ||----||
^^ ^^ * ||------|| ^^ ^^ ^^ ^^
^^ ^^
Cownt Dracula Francownstein Where Cow Cow bird
Cow Cow
```

Start by locating the ContractFactory classes and the code that creates the contract object shown in the example. Determine how the source contract name is available there; done means the resulting contract object exposes that name rather than the generic PopulusContract class name.

Written by the indexing model from the issue text.