software up to date

Gemfile.lock

PATH
  remote: .
  specs:
    et (1.1.0)
      rest-client (~> 1.7)
      sinatra (~> 1.4)
      sinatra-contrib (~> 1.4)

GEM
  remote: https://rubygems.org/
  specs:
    backports (3.6.4)
    docile (1.1.5)
    domain_name (0.5.24)
      unf (>= 0.0.5, < 1.0.0)
    et-plugin (0.2.0)
    http-cookie (1.0.2)
      domain_name (~> 0.5)
    metaclass (0.0.4)
    mime-types (2.5)
    minitest (5.4.2)
    mocha (1.1.0)
      metaclass (~> 0.0.1)
    multi_json (1.10.1)
    netrc (0.10.3)
    rack (1.5.2)
    rack-protection (1.5.3)
      rack
    rack-test (0.6.2)
      rack (>= 1.0)
    rake (10.3.2)
    rest-client (1.8.0)
      http-cookie (>= 1.0.2, < 2.0)
      mime-types (>= 1.16, < 3.0)
      netrc (~> 0.7)
    simplecov (0.9.1)
      docile (~> 1.1.0)
      multi_json (~> 1.0)
      simplecov-html (~> 0.8.0)
    simplecov-html (0.8.0)
    sinatra (1.4.6)
      rack (~> 1.4)
      rack-protection (~> 1.4)
      tilt (>= 1.3, < 3)
    sinatra-contrib (1.4.2)
      backports (>= 2.0)
      multi_json
      rack-protection
      rack-test
      sinatra (~> 1.4.0)
      tilt (~> 1.3)
    tilt (1.4.1)
    unf (0.1.4)
      unf_ext
    unf_ext (0.0.7.1)

PLATFORMS
  ruby

DEPENDENCIES
  bundler (~> 1.5)
  et!
  et-plugin (~> 0.2)
  minitest
  mocha
  rack (~> 1.5)
  rack-test (~> 0.6)
  rake
  simplecov

latest_gem.rb

require 'bundler'
require 'net/http'
require 'json'
require 'uri'

# read Gemfile.lock
gemfile = File.read("./Gemfile.lock")
specs   = Bundler::LockfileParser.new(gemfile).specs
data = specs.map.each do |spec|
  base = "https://rubygems.org/api/v1/gems/" #backports.json
  gem  = "#{spec.name}.json"
  uri  = URI(base + gem)
  response = Net::HTTP.get(uri)
  begin
    current_gem = JSON.parse(response)
  rescue => e
    next
  end
  latest_version    = current_gem["version"]
  lock_version      = spec.version.to_s
  # compare versions
  upgrade_available = Gem::Version.new(lock_version) < Gem::Version.new(latest_version)
  {spec.name => {lock_version: lock_version, latest_version: latest_version, upgrade_available: upgrade_available}}
end

p data

output.txt

[{"backports"=>{:lock_version=>"3.6.4", :latest_version=>"3.8.0", :upgrade_available=>true}}, {"docile"=>{:lock_version=>"1.1.5", :latest_version=>"1.1.5", :upgrade_available=>false}}, {"domain_name"=>{:lock_version=>"0.5.24", :latest_version=>"0.5.20170404", :upgrade_available=>true}}, {"et"=>{:lock_version=>"1.1.0", :latest_version=>"0.6.2", :upgrade_available=>false}}, nil, {"http-cookie"=>{:lock_version=>"1.0.2", :latest_version=>"1.0.3", :upgrade_available=>true}}, {"metaclass"=>{:lock_version=>"0.0.4", :latest_version=>"0.0.4", :upgrade_available=>false}}, {"mime-types"=>{:lock_version=>"2.5", :latest_version=>"3.1", :upgrade_available=>true}}, {"minitest"=>{:lock_version=>"5.4.2", :latest_version=>"5.10.2", :upgrade_available=>true}}, {"mocha"=>{:lock_version=>"1.1.0", :latest_version=>"1.2.1", :upgrade_available=>true}}, {"multi_json"=>{:lock_version=>"1.10.1", :latest_version=>"1.12.1", :upgrade_available=>true}}, {"netrc"=>{:lock_version=>"0.10.3", :latest_version=>"0.11.0", :upgrade_available=>true}}, {"rack"=>{:lock_version=>"1.5.2", :latest_version=>"2.0.3", :upgrade_available=>true}}, {"rack-protection"=>{:lock_version=>"1.5.3", :latest_version=>"2.0.0", :upgrade_available=>true}}, {"rack-test"=>{:lock_version=>"0.6.2", :latest_version=>"0.6.3", :upgrade_available=>true}}, {"rake"=>{:lock_version=>"10.3.2", :latest_version=>"12.0.0", :upgrade_available=>true}}, {"rest-client"=>{:lock_version=>"1.8.0", :latest_version=>"2.0.2", :upgrade_available=>true}}, {"simplecov"=>{:lock_version=>"0.9.1", :latest_version=>"0.14.1", :upgrade_available=>true}}, {"simplecov-html"=>{:lock_version=>"0.8.0", :latest_version=>"0.10.1", :upgrade_available=>true}}, {"sinatra"=>{:lock_version=>"1.4.6", :latest_version=>"2.0.0", :upgrade_available=>true}}, {"sinatra-contrib"=>{:lock_version=>"1.4.2", :latest_version=>"2.0.0", :upgrade_available=>true}}, {"tilt"=>{:lock_version=>"1.4.1", :latest_version=>"2.0.7", :upgrade_available=>true}}, {"unf"=>{:lock_version=>"0.1.4", :latest_version=>"0.1.4", :upgrade_available=>false}}, {"unf_ext"=>{:lock_version=>"0.0.7.1", :latest_version=>"0.0.7.4", :upgrade_available=>true}}]