Release 1.0.0: Fix behaviour of Brex.none

- BREAKING: `Brex.none` now only succeeds if every rule fails (before it only already succeeded when a single rule failed)

Release 0.2.3: Make compatible with Elixir 1.10

Release 0.2.2: Fix an critical issue about a missing version file

The version file is now part of the package and only read at compile
time instead of runtime.

Fix Brex.none/1 behaviour for empty lists

The behaviour of `Brex.none/1` was confusing for an empty list of rules, due simply inverting the result of `Brex.all/1`. This release introduces a special handling for an empty list of rules:

```elixir
iex> rules |> Brex.none() |> Brex.satisfies?(:whatever)
false
```

```elixir
iex> rules |> Brex.none() |> Brex.satisfies?(:whatever)
true
```

Brex v0.2.0:

This release introduces a greatly simplified Operator generation. I've
realised that the former implementation basically was reimplementing
structs in a shitty manner. As such the `Brex.Operator` is now simply a
struct with an `aggregator` and a `clauses` field.

For details take a look at the `Brex.Operator` moduledocs.

Brex 0.1.0 - First release

Introduces basic functionality which includes:
- rules (functions, modules, structs)
- operators (all, any, none)
- a formatter behaviour
- the result struct

It also includes hopefully extensive documentation and a helpful README.