Remove unnecessary Java module include

There is no need to include Java module in main object.
It allows to call java classes without 'Java::' prefix but this functionality should be application specific and not forced by gem.

```ruby
>> self.class.ancestors
[
  [0] Object < BasicObject,
  [1] Kernel,
  [2] BasicObject
]
>> require 'babosa'
true
>> self.class.ancestors
[
  [0] Object < BasicObject,
  [1] Java,
  [2] Kernel,
  [3] BasicObject
]
>>
```