Cast attributes before forwarding to updater
Order by clustering column.
fail fast attempting to save a model that doesn't have all keys defined
don't allow updating keys on persisted models (#37)
Move key enforcement to persistence operations

We should be able to call #key_attributes without error even if they're not all
populated
Remove modifications to .gitignore
Add spec for correct ordering column
Order by column has to be a clustering column

RecordSet will fail fast if you try to reverse a record set that isn't scoped
to a single partition.
Merge branch 'order-by-clustering-column'

* order-by-clustering-column:
  Order by column has to be a clustering column
  Add spec for correct ordering column
  Remove modifications to .gitignore
  Order by clustering column.
Cast attributes before forwarding to updater
Merge pull request #43 from cequel/collection-cast

Clearing a pre-existing value in a Set
Cast elements passed as arguments to List mutator methods
Line numbers
Allow passing other flags to script/spec
Type casting for Set elements in mutator methods
Cast keys and values in map update operations
Refactor Type a bit

* Use casting methods `String()`, `Integer()`, `Float()`, etc.
* Simpler template method for String types
* Always return times in UTC (since Cassandra doesn't store TZ data)
Cast arguments to scoping functions of `RecordSet`
Specs for Timeuuid range queries

I forget exactly how this works and I'm on an airplane, so no actual
implementation here.
Working timeuuid support