Rename Dice#balanced? to #fair?

* Keep #balanced? as an alias
Add Dice#loaded? as an alias to Dice#crooked?
Fix wording in documentation
Merge pull request #37 from rafaelgonzalez/rename-dice-crooked

Rename Dice#balanced? and add alias do Dice#crooked?
Merge pull request #38 from rafaelgonzalez/fix-documentation

Fix wording in documentation
Add dependencies status badge