test-lessons.sh: Test mock-up lesson packaging with Bower

This shell script lets you test Bower-based packaging locally.  Note
that semver has stricter compatibility requirements for ^0.x [1]:

> ^0.1.3 := >=0.1.3-0 <0.2.0-0 "Compatible with 0.1.3". 0.x.x versions
> are special: the first non-zero component indicates potentially
> breaking changes, meaning the caret operator matches any version
> with the same first non-zero component starting at the specified
> version.

So of 0.1.0, 0.1.1, and 0.2.0, ^0.1 will match all but 0.2.0.  That
means the script currently wraps up with:

  workshop /tmp/z/workshop
  └─┬ git-lesson#0.1.0 extraneous
    └── shell-lesson#0.1.1 (latest is 0.2.0)

[1]: https://github.com/isaacs/node-semver#ranges
test-lessons.sh: Avoid special ^0.x.x handling by using 0.*

Minor version bumps happen too frequently for this dummy project ;).
Float the version until the shell lesson makes it to 1.0.0.
test-lessons.sh: Add a workshop collection repository

As an example of what Software Carpentry would provide as a workshop
template.  Running this version of the script ends with:

  .
  ├── README.md
  ├── bower.json
  └── bower_components
      ├── git-lesson
      │   ├── README.md
      │   └── bower.json
      └── shell-lesson
          ├── README.md
          └── bower.json

  3 directories, 6 files
  bower check-new     Checking for new versions of the project dependencies..
  swc-workshop /tmp/student-workshop
  └─┬ git-lesson#0.1.0
    └── shell-lesson#0.2.0
test-lessons.sh: Use tabs and spaces to indent here-documents

When you create a here-document with '<<-', leading tabs are stripped
[1].  Because I still want indentation in the bower.json files, I
guess I'll have to use spaces for the indentation I want to preserve.

[1]: http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_07_04
Merge pull request #3 from wking/test-script

test-lessons.sh: Test mock-up lesson packaging with Bower
test-lessons.sh: Slot in a custom, per-workshop shell lesson

Running this version of the script ends with:

  swc-workshop /tmp/student-workshop
  ├─┬ git-lesson#0.1.0
  │ └── shell-lesson#0.3.0 (0.2.0 available)
  └── shell-lesson#0.3.0
Merge pull request #4 from wking/test-script

test-lessons.sh: Slot in a custom, per-workshop shell lesson
added some informative logs during my reading of the test-lessons.sh
added a replacement when "tree" is not found (in the train...)
shortcut to repush the tag
skeleton for the script
Add how to