Init User Flow Rework

[awood45]

Issue #, if available:

Description of changes:

Checklist:

• Write Design Document (Do I need to write a design document?)
• Write unit tests
• Write/update functional tests
• Write/update integration tests
• make pr passes
• Write documentation

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[sriram-mv]

Generally looks good, can you post a screenshot of what the experience looks like?

[awood45]

Example:

$ samdev init
Which template source would you like to use?
        1 - AWS Quick Start Templates
        2 - Custom Template Location
Choice: 1
 
Which runtime would you like to use?
        1 - nodejs10.x
        2 - python3.7
        3 - ruby2.5
        4 - go1.x
        5 - java8
        6 - dotnetcore2.1
        7 - nodejs8.10
        8 - nodejs6.10
        9 - python3.6
        10 - python2.7
        11 - dotnetcore2.0
        12 - dotnetcore1.0
Runtime: 2
 
Project name [sam-app]: python-app
 
Quick start templates may have been updated. Do you want to re-download the latest [Y/n]:
 
-----------------------
Generating application:
-----------------------
Name: python-app
Runtime: python3.7
Dependency Manager: pip
Application Template: hello-world
Output Directory: .
 
Non-interactive init command with parameters:
 
    sam init --name python-app --runtime python3.7 --dependency-manager pip --app-template hello-world --output-dir .
 
Next steps can be found in the README file at ./python-app/README.md