Adds an init script that uses the local version of the provider

[alessandroargentieri]

Addition of a script that sets the local version of the civo terraform provider by taking care of:

• create/override the ~/.terraformrc file
• create the provider.tf in the destination folder with the local version of the provider
• building the binary of the provider from the current branch and moving it into the destination folder
• performing a terraform init and a terraform plan

The script takes care of checking if golang, civo CLI and terraform are installed.

[alejandrojnm]

Can you add to the readme, something like this is for local dev

[alessandroargentieri]

@alejandrojnm Do you mean that the README.md changes you find in this PR are not exhaustive?

[alejandrojnm]

Yes is ok, but you put it in the make build section, and this change is for local development, add a new section in the readme for a local dev.