Provide autocomplete API with language specification.

[abargnesi]

Motivation

The bel.rb gem provide a completion API that can autocomplete BEL terms. Currently the implementation hard-codes a BEL 1.0 language specification. The completion APIs should be given a language specification to use when completing. This will allow a user to complete terms for BEL 1.0, 2.0, and up.

Tasks

• Add bel_parser as a runtime gem dependency to bel.rb.
• Update bel.rb's completion API (lib/bel/completion.rb, lib/bel/completion_rule.rb) to receive a BEL specification.
  • See BEL::Language module for retrieving specifications from bel_parser.
• Use the provided BEL specification to complete functions names.
• Update the /api/completion route in OpenBEL API to pass the configured BEL specification to the completion API (defined by bel.rb).