Ability to make a unique index
Merge pull request #110 from codeaholics/unique-index

Add ability to make a unique index
Add ability to create camel cased column names for Postgres
update docs for version 0.5.2
Added backticks to mysql driver
Fixed bug setting default values to values that are falsy
Check for undefined value rather than typeof 'undefined'
Update docs for v0.5.3, closes #114
Added backticks to mysql driver
Update docs for version 0.5.4