Added Pry to the test group to aid in debugging.
Added Pry to the testing suite.
Fixed failing datetime tests.

The failures were specific to xlsx format spreadsheets. When setting the date time to a string format, we need to round to the nearest second.
Fixed edge case involving date time string with seconds.

When supplying a date time string with seconds (11/5/2013 11:45:00), the resulting DateTime object would not round the fractional seconds resulting in a time string of 11/5/2013 11:44:59. 

Time is now properly rounded before returning the DateTime object.
README clarification

Roo::Spreadsheet requires spreadsheet gem
Handle link celltype when writing to csv for .xls
Fix parsing of .xlsx files exported from Numbers

Numbers 3.1 can export .xlsx files, but the feature has some
incensistencies and bugs.

This commit fixes an inconsistency where the first sheet doesn't have
have an index in the XML filename ("sheet.xml"), whereas such sheet
would be named "sheet1.xml" by Excel.

This fix is inspired by a solution provided in #110.
Prevent inspect from being called recursively
fixed an xlsx format bug where formating containing [red] would get picked up as date
Merge pull request #104 from jrmyward/fix_xlsx_datetimes

Fix xlsx datetimes
Merge pull request #106 from SheetJSDev/patch-1

README clarification
Merge pull request #120 from EricBel/master

fixed an xlsx format bug - format containing [red] was converted to date
Merge pull request #114 from sidonath/fix-numbers-xlsx-parsing

Fix parsing of .xlsx files exported from Numbers
Merge pull request #115 from whistlerbrk/master

Prevent inspect from being called recursively
Merge pull request #108 from data-axle/master

Handle link celltype when writing to csv for .xls
Bump rspec version to > 2.14
Tidy up Roo::Base#find, #find_by_row, #find_by_conditions.
Only apply URI parsing if the path is a URI. Fixes #121.

Alternative fix to 268adb5f.
Fix error in test helper file_diff
Added test for nil in Roo::Excelx#read_hyperlinks to avoid error "NoMethodError (undefined method `text' for nil:NilClass)"