Change virtual environment name on README

[vanessa]

Description

• Change virtual environment names when using virtualenvwrapper or normal virtualenv package
• Fix paths to SERVER_EMAIL and ADMINS change step (closes #459)

Motivation and Context

• When using virtualenvwrapper, the created virtual environment isn't added to the root directory, but rather in a directory in $HOME, so we don't have to worry about it being added to source control and what name it is, so it's ok to have the virtualenv with the same name as project's.
• When using Python's virtualenv package, the directory is created at root level and should be the name of what we add to .gitignore and linter configs so that the files inside it are ignored from any processes we run. That's why it's important to instruct the user to name it venv.
• If someone creates a virtualenv with the name of the project, as instructed by the setup steps, it'll end up being added to source control, so if the person has CircleCI integrated, the linters will run and catch some problems inside the virtual environment folder. That's not something we want.

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] My code follows the code style of this project.
• [x] My change requires documentation updates.
• [x] I have updated the documentation accordingly.
• [ ] My change requires dependencies updates.
• [ ] I have updated the dependencies accordingly.

[vanessa]

@davidpierre21 You mean adding something like {{project_name}}/ to .gitignore? So when the user start the project and name it theprojectname AND create the virtualenv with the same name, it'll be ignored, right?

[davidpalves]

@vanessa Yes, something like that. Maybe a prefix or suffix, like {{project_name}}-venv or something like this, so it wouldn't ignore the project directory itself, if it makes any sense. Although using something like venv is way simpler, for someone who's nor familiar with virtual environments, it might conflict with some other existing environment. What do you think? :smiley: