allow_value.with_message takes i18n interp values
v_n_o no longer treats numbers as floats

Essentially validate_numericality_of when used with a comparison
qualifier required you to use only_integer when the validation itself
had only_integer on it, because the boundaries of the comparison were
tested using small decimal numbers rather than whole numbers. This
change was introduced in bc110f7, but is obviously is a backward
incompatible change, so we are reverting it.
Fix tests for ComparisonMatcher to use proper error messages
Bump to version 2.6.1.rc2
Bump version to 2.6.1
Speed up repeated execution of unit tests

In the Cucumber tests, we do not access the Internet to install test
dependencies -- we assume that you've already run `bundle install` or
`appraisal install` to install those dependencies. Change the RSpec
tests so that the same thing happens.
Check correct columns are present in join table

The `have_and_belong_to_many` matcher could give a false positive if the
join table is present but does not contain the correct columns. Check to
see if the columns exist in the join table and provide a meaningful
failure message if one or more of the columns are not present.
Extract JoinTableVerifier class

Avoid growing AssociationMatcher by extracting join table verification
code into its own class.
Test joining of missing columns with ','
Use submatcher pattern for JoinTableMatcher
Make AssociationMatcher#add_submatcher public

Adding the join table submatcher during intial creation of the
association matcher necessitates calling `add_submatcher`. Make the
method public to avoid the having to use `send`.
Use single quotes for non-interpolating strings
Check associated class exists in JoinTableMatcher

*This fixes the failing tests for Rails 4.0/4.1*

Rails 4.0 and 4.1 have different mechanisms for deriving the name of the
join table for an association which involves accessing the actual
associated class. This raises a NameError if the associated class does
not actually exist, causing existing tests to fail with an unexpected
exception.

Before, when join table existence was being checked in the main matcher,
`join_table_exists?` would not be called if the associated class didn't
exist because it would be short-circuited by `class_exists?`. Now that
join table verification has been extracted to a submatcher, the check
for join table existence *always* runs. This means the potential
NameError mentioned above would be raised in Rails 4+.

Thus, we add a check for the existence of the associated class before
checking for the existence of a join table, causing the same
short-circuit as was originally in place.
Different strategy for JoinTableMatcher

Simply using JoinTableMatcher as a submatcher required a couple of
awkward compromises. Use a more explicit approach to checking for a join
table.
Remove call to `class_exists?` in JoinTableMatcher