Stripe fails on macbook localhost but works on iMac localhost - ruby

Question

I have integrated Stripe into my Ruby Application. When testing on LocalHost on my iMac everything works fine.
The deployment in production works fine
When testing on my MacBook Pro it errors out on submission. The MacBook and iMac are using the same operating systems. iMac late 2014, MacBook late 2016.
This is my first stripe integration and I am stumped.
There are no differences in code, and so I am considering that the environment is not initialising, but I don't know what the issue is.
The error is as follows:
"No API key provided. Set your API key using "Stripe.api_key = "
Showing the following code as the culprit - But remember this works well on two other installations and so I can't see it being the code at fault (But I am happy to be wrong if you all have other ideas!)
Stripe::Customer.retrieve(stripe_id)
else
stripe_customer = Stripe::Customer.create({
email: email,
})
This is the config file
stripe.rb
Rails.configuration.stripe = {
:publishable_key => ENV["STRIPE_TEST_PUBLISHABLE_KEY"],
:secret_key => ENV["STRIPE_TEST_SECRET_KEY"]
}
Stripe.api_key = Rails.configuration.stripe[:secret_key]
StripeEvent.configure do |events|
events.subscribe "charge.succeeded", Webhooks::ChargeSucceeded.new
events.subscribe "customer.subscription.deleted",
Webhooks::CustomerSubscriptionDeleted.new
end