Implement complete tesselinclude detect spec

[rwaldron]

1. Update t2 init to auto-create a .tesselinclude file, that contains the following:

# This file should list any files or directories you want included with the 
# T2 bundling and deployment process. This is handy for including 
# non-JavaScript assets, like HTML, CSS, and images, for use within your project.
# .tesselinclude works the same as .npminclude 
# You DO NOT need to list node_modules or package.json
# For more information, visit: https://tessel.io/docs/cli#usage

1. Update t2 run and t2 push operations:
   1. Read the entry point file's directory (which is globRoot, not './' *) as list
      1. If list does not include .tesselinclude, do the following:
         1. If list.length is 3 and list includes node_modules, list includes [opts.resolvedEntryPoint] and list includes package.json, do nothing
         2. Else,
            1. If list.length is > 3,
               1. Let assets be an empty array
               2. Foreach entry in list, if [opts.resolveEntryPoint, 'node_modules', 'package.json'].includes(entry) === false, push entry into assets
               3. To the console, print: "The following items were found in your project:"
               4. list.forEach(entry => console.log(\${entry})
               5. To the console, print: "If you need to deploy them to your tessel, you must create a .tesselinclude file that contains the items you wish to deploy with your application."

This spec should be sufficient to meet the requirements and only costs a single readdirSync.

* The current patch assumes that t2 run ... or t2 push ... is always called from the project directory, which is an invalid assumption.