feat: adds Date support to escapeCQL function
fix: escapeCql handles invalid date objects
tests: adds tests for timestamps
fix: separated the different timestamps (current, future, pre-epoch) out into their own tests
fix: handles pre-epoch dates for cassandra < 2.*
fix: escapes date as iso string in utc to work with all versions of cql
fix (datetype): uses long if post-epoch date, datestring for pre, to account for https://issues.apache.org/jira/browse/CASSANDRA-6212
Merge pull request #131 from tim-dev/master

feat: adds Date support to escapeCQL function