This way, we can recognize when when is a test

TEST will be one.  Parsed as an Arrow with a dummy lhs

Now creates a nullary function containing the test's code rather than
just computing the location of the string.

We get most of the desired methods for free via inheritance.

We keep TestInput around as a synonym for now

We call each test, and if it returns a string, then it's a traditional test
that we should try to capture.  Otherwise, we're done!

A couple things:

- Tests run this way don't produce any output, so debugging is harder.  In
  particular, Verbose => true doesn't do anything.
- We print "calling" *after* we're done running the test, since we don't know
  if it returns a string or not.

Run a test, and if it returns a string (i.e., it's a traditional
test), then capture that string.

currentFileDirectory will no likely no longer be the correct path to
the test files, so we use the packages' "auxiliary files" keys to find
them.

Also bump package to version 0.2

Otherwise we'll actually add a test to the current package.

Also add "tests" to SeeAlso section

List of files to install in package test directory when running
installPackage.

Also bump the version number of JSON