This explains how to resolve the 401 Unauthorized status code and redirect your twitter app.

devise.rb

# Lastly, Changing in OmniAuth.rb will affect this file too.
# Change this line in order to fully work and restart the server when you save this file.
# ...viola! You now have profit to make.
Devise.setup do |config| 
	config.omniauth :twitter, Rails.application.secrets.twitter_consumer_key, Rails.application.secrets.twitter_consumer_secret
end

omniauth.rb

# Next, you will need to change this line of code to work this out.
# This will rertrieve the keys from config/secrets.yml
Rails.application.config.middleware.use OmniAuth::Builder do
	provider :twitter, Rails.application.secrets.twitter_consumer_key, Rails.application.secrets.twitter_consumer_secret
end

secrets.yml

# In order to OmniAuth-Twitter gem to work, you will need to place your keys on
# to this file.

twitter_consumer_key: [your consumer key here]
twitter_consumer_secret: [your consumer secret here]