Data tables

When steps have a data table, they are passed an object with methods that can be used to access the data.

with column headers
- hashes: returns an array of objects where each row is converted to an object (column header is the key)
- rows: returns the table as a 2-D array, without the first row
without column headers
- raw: returns the table as a 2-D array
- rowsHash: returns an object where each row corresponds to an entry (first column is the key, second column is the value)
- transpose: returns a new instance with the data transposed

See this feature for examples