Use SVG badge for Travis
bump deps
code style
main.js => index.js
Fix `#determineAppname()` to always find a name
Feature Base#gruntfile expose a gruntfile-editor API

That allow multiple generator from adding configurations to the
gruntfile.js without creating conflicts when writing the file.
Check for git prior to calling shell.exec
Add comment for registerValidationFilter entries.
Typo correction in methodIsValid comment
Fix task queue names
Version 0.17.0-pre.3
Changes appendStyles and appendScripts to be a compelete alias to appendFiles

See #536
Clarify assert.file API documentation
Allow helpers.mockPrompt to work without arguments

Fix #538, fix #539
"Description" help text + general cleanup

Squashed commits:
[f6d094a] PR review changes
[cdb4485] description help text for arguments

- removed unused `help.bannerFor()`
- updated some JSDoc
- option defaults no longer display if default value is an empty string
- rewrote unit tests for `help.help()` function
    - the old tests made it difficult to debug since Mocha would only report truthiness
    - using the updated method, we now compare strings and can easily see any differences as reported by the assertions
    - I also elected to ignore extra whitespace here, because I want to test the content; not the `text-table` module's output.
[8ad7e91] general cleanup: removing some unused vars, updating some JSDoc tags & comments, simplified expression
Fix a RunContext so it run only once

There was a race condition causing a generator to run multiple times if
the temp directory rimraf action was too fast.
Feature: RunContext mock prompt by default

Also ensure helper.mockPrompt keep the prompt asynchronous and keep the
origin reference to the initial prompt method when called multiple times.

Fix #539
Fail build if static analysis doesn't pass
Fix style guide errors
Default options to `undefined`.

This matches a JS function, where params that are not matched default to
undefined.