`be_true` and `be_false` are deprecated

Replace with `be true` and `be false` and make predicate return a
boolean.

> Methods that don't return a boolean, shouldn't end in a question mark.
-- https://github.com/bbatsov/ruby-style-guide#naming
Failing spec to describe my problem
Handle quotation marks in section names

The section name appears on a line by itself, in square brackets (`[` and
`]`), all characters between the opening `[` and the closing `]` should
be considered to form the section name.
Merge branch 'deprecation-warnings' into handle-quotation-marks-in-section-names

This should fix the build.

If this change isn't desired,
./spec/unit/puppet/provider/ini_setting/ruby_spec.rb:1044 could be
changed to:

```ruby
provider.exists?.should be_nil
```
Test allowing $ signs in section names

Verifying that this PR addresses https://github.com/puppetlabs/puppetlabs-inifile/pull/98
Merge remote-tracking branch 'origin/master' into handle-quotation-marks-in-section-names
Spec for MODULES-1194

Ini_file module does not recognize section names with forward slashes in them

https://tickets.puppetlabs.com/browse/MODULES-1194
Merge pull request #115 from johnsyweb/handle-quotation-marks-in-section-names

Handle quotation marks in section names