Codify dependency on EtOrbi::EoTime#to_local_time (#5)

* Codify dependency on `EtOrbi::EoTime#to_local_time`

The code as written depends on the `EtOrbi::EoTime#to_local_time`
method. However, this method was not introduced until `et-orbi`
version `1.0.6`.

In cases where the bundle already contains a version of `et-orbi` that
is not updated to `1.0.6`, the code fails to execute because the
method does not exist yet.

fixes #4

* Alphabetize gem dependencies

que-scheduler.gemspec

@@ -19,6 +19,7 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency 'activesupport', '>= 3.0'
   spec.add_dependency 'backports', '~> 3.10'
+  spec.add_dependency 'et-orbi', '> 1.0.5' # need the `#to_local_time` method
   spec.add_dependency 'fugit', '~> 1'
   spec.add_dependency 'hashie', '~> 3'
   spec.add_dependency 'que', '~> 0.10'