Broken support for "or expressions" in filters

[elyobo]

The specification allows for "or expressions" in filters, but jmespath.rb seems to only have partial support.

require 'jmespath'

# Results in undefined method `empty?' for true:TrueClass, should match
JMESPath.search('[?foo || bar]', [{foo: true, bar: false}])

# Results in empty an empty array, should match
JMESPath.search("[?foo == 'foo' || bar == 'foo']", [{foo: "foo", bar: "bar"}])

# Results in empty an empty array, should match, trying different delimiters
JMESPath.search('[?foo == `"foo"` || bar == `"foo"`]', [{foo: "foo", bar: "bar"}])
``

[iconara]

The first case is fixed by #15

[elyobo]

Thanks @iconara

[trevorrowe]

#15 has been merged and there have been various other expression and comparison fixes.