Make 'rake build' and 'rake install' work again

This needs require 'bundler/gem_tasks' in Rakefile
Only raise if w > 0
Failing delete document spec helper
Just return result if w = 0
Merge lists in bulk objects, don't append
RUBY-787 Batch classes
RUBY-787 Special bulk insert result
RUBY-787 Specs for insert portion of Bulk API
RUBY-787 minor cleanup
RUBY-787 Build response hash
Fix documentation typo
Merge pull request #494 from estolfo/bulk-2

Bulk API classes and functionality for doing insert operations with the Bulk API
Update explain test for new format in 2.7
Update Delete specs for stricter server limit checks
RUBY-787 Use upsert instance variable so not confused with API method
RUBY-787 Bulk Update and specs
RUBY-787 Don't clear out n to 0 when processing replies
RUBY-787 Cleanup bulk update logic and specs
RUBY-787 Constants for accessing fields in update result doc
Merge pull request #495 from estolfo/bulk-2

Bulk API Update operations