Split testing into unit and functional tests.

* Split the `test` nimble task into `unittest` and `functest`, with
  corresponding test directories and test runners.
* Added documentation in README regarding building and testing StrawBoss.
* Created a small, simple test project for use in the functional tests.
* Added a `keepEnv` template in the server unit test code to make it easy to
  preserve the working environment for a single unit test to invistigate
  failures manually.

README.md

@@ -219,3 +219,43 @@ using the handler to update the supervisor's knowledge of the build results and
 
 When launched in single-build mode there is no supervisory process. The main
 process directly executes the requested build steps.
+
+### Building StrawBoss
+
+To build StrawBoss locally, checkout the repository and in the repo root run:
+
+    nimble build
+
+### Testing
+
+StrawBoss has two test suites, a set of unit tests and a set of functional
+tests. All the test code and assets live under the `src/test` subdirectory.
+
+Each test suite has a runner file that serves as an entry for the test process,
+named `run_unit_tests.nim` and `run_functional_tests.nim`.
+
+#### Unit Tests
+
+The unit test soruce files live in the `nim/unit` subdirectory and have a
+one-to-one correspondence with the StrawBoss source files following this
+naming convention: `t<module>.nim`. The unit tests are intended to be run any
+time the code is recompiled.
+
+To run the unit tests, use the `unittest` nimble task:
+
+    nimble unittest
+
+#### Functional Tests
+
+The functional test source files live in the `nim/functional` subdirectory.
+There is a test project that is used to excercise StrawBoss functionality. To
+avoid external coupling it is stored within the StrawBoss repository as a test
+asset. To avoid `git` complications it is stored as a Gzipped TAR file and
+unpacked to a temporary directory as part of the functional test process.
+
+As the functional tests are more time-consuming and intensive, they are
+expected to bu run when performing a build.
+
+To run the functional tests, use the `functest` nimble task:
+
+    nimble functest