GetWhereAsync not working with Equals method

lambda expression type not supported. I was trying this

```csharp
var customer = await cn.GetWhereAsync<Customer>(model => model.Path.Equals(blob.CustomerPath));
```

but it didn't like me using `Equals`. I had to re-phrase like this

```csharp
var customer = await cn.GetWhereAsync<Customer>(model => model.Path == blob.CustomerPath);
```
and it worked -- but the first case should work