Getting error during bundle

[w3villa-amit]

Hello i am trying to add the gem 'spree_active_shipping', github: 'spree-contrib/spree_active_shipping',branch: '3-1-stable'
and after doing bundle i got -:
Bundler could not find compatible versions for gem "spree_core":
In snapshot (Gemfile.lock):
spree_core (= 3.4.5)

In Gemfile:
spree (~> 3.4.0) was resolved to 3.4.5, which depends on
spree_core (= 3.4.5)

spree_active_shipping was resolved to 3.1.0, which depends on
  spree_core (~> 3.1.0.beta)

Running bundle update will rebuild your snapshot from scratch, using only
the gems in your Gemfile, which may resolve the conflict.

and my gemfile is -:
source 'https://rubygems.org'
ruby '2.3.1'

git_source(:github) do |repo_name|
repo_name = "#{repo_name}/#{repo_name}" unless repo_name.include?("/")
"https://github.com/#{repo_name}.git"
end

Bundle edge Rails instead: gem 'rails', github: 'rails/rails'

gem 'rails', '~> 5.1.4'

Use mysql as the database for Active Record

gem 'mysql2', '>= 0.3.18', '< 0.5'

Use Puma as the app server

gem 'puma', '~> 3.7'

Use SCSS for stylesheets

gem 'sass-rails', '~> 5.0'

Use Uglifier as compressor for JavaScript assets

gem 'uglifier', '>= 1.3.0'
gem 'nokogiri', '1.6.6.2'

See https://github.com/rails/execjs#readme for more supported runtimes

gem 'therubyracer', platforms: :ruby

Use CoffeeScript for .coffee assets and views

gem 'coffee-rails', '~> 4.2'

Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks

gem 'turbolinks', '~> 5'

Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder

gem 'jbuilder', '> 2.5'
gem 'friendly_id', '> 5.2.0'
gem 'pry'
gem 'stripe'
gem 'gaffe'
gem 'papercrop'
gem 'social-share-button'
gem 'rack-tracker'

gem "nested_form"

Use Redis adapter to run Action Cable in production

gem 'redis', '~> 3.0'

Use ActiveModel has_secure_password

gem 'bcrypt', '~> 3.1.7'

Use Capistrano for deployment

gem 'capistrano-rails', group: :development

gem 'paypal-sdk-rest'
gem 'whenever', require: false
gem 'twilio-ruby','>4.2.1'
gem "figaro"
gem 'spree', '> 3.4.0'
gem 'spree_auth_devise', '> 3.3'
gem 'spree_gateway', '> 3.3'
gem 'slim-rails'
gem 'sunspot_rails'
gem "font-awesome-rails"
gem "paperclip", ">= 5.0"
gem "aws-sdk", ">= 2.0"
gem 'sidekiq'
gem 'spree_editor', github: 'spree-contrib/spree_editor'
gem 'spree_paypal_express', github: 'spree-contrib/better_spree_paypal_express'
gem 'spree_taxjar', github: 'vinsol-spree-contrib/spree_taxjar'
gem 'recaptcha', :require => 'recaptcha/rails'
gem 'spree_active_shipping', github: 'spree-contrib/spree_active_shipping',branch: '3-1-stable'

gem 'bootstrap-datepicker-rails'

group :development, :test do

Call 'byebug' anywhere in the code to stop execution and get a debugger console

gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]

Adds support for Capybara system testing and selenium driver

gem 'capybara', '~> 2.13'
gem 'selenium-webdriver'
end

group :development do

Access an IRB console on exception pages or by using <%= console %> anywhere in the code.

gem 'web-console', '>= 3.3.0'
gem 'listen', '>= 3.0.5', '< 3.2'

Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring

gem 'spring'
gem 'sunspot_solr'
gem 'spring-watcher-listen', '~> 2.0.0'
end

Windows does not include zoneinfo files, so bundle the tzinfo-data gem

gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]

group :development do
gem 'capistrano', '3.7.2', require: false
gem 'capistrano-rvm', require: false
gem 'capistrano-rails', require: false
gem 'capistrano-bundler', require: false
gem 'capistrano3-puma', '1.2.1', require: false
gem 'capistrano3-delayed-job', '~> 1.0'
gem 'letter_opener'
end

Please help.