Teach rake to run all python tests as a group

docs/internal/testing.md

@@ -86,10 +86,12 @@ because the `capa` package handles problem XML.
 
 # Running Tests
 
-Before running tests, ensure that you have all the dependencies.  You can install dependencies using:
+You can run all of the unit-level tests using the command
 
-    rake install_prereqs
+    rake test
 
+This includes python, javascript, and documentation tests. It does not, however,
+run any acceptance tests.
 
 ## Running Python Unit tests
 
@@ -97,15 +99,15 @@ We use [nose](https://nose.readthedocs.org/en/latest/) through
 the [django-nose plugin](https://pypi.python.org/pypi/django-nose)
 to run the test suite.
 
-You can run tests using `rake` commands.  For example,
+You can run all the python tests using `rake` commands.  For example,
 
-    rake test
+    rake test:python
 
 runs all the tests.  It also runs `collectstatic`, which prepares the static files used by the site (for example, compiling Coffeescript to Javascript).
 
-You can re-run all failed python tests by running (all JS tests will still run)
+You can re-run all failed python tests by running
 
-    rake test[--failed]
+    rake test:python[--failed]
 
 You can also run the tests without `collectstatic`, which tends to be faster:
 

rakelib/tests.rake

@@ -159,11 +159,16 @@ TEST_TASK_DIRS.each do |dir|
     report_dir = report_dir_path(dir)
     directory report_dir
     task :report_dirs => [REPORT_DIR, report_dir]
-    task :test => "test_#{dir}"
+    task 'test:python' => "test_#{dir}"
+end
+
+namespace :test do
+    desc "Run all python tests"
+    task :python, [:test_id]
 end
 
 desc "Run all tests"
-task :test, [:test_id] => :test_docs
+task :test, [:test_id] => [:test_docs, 'test:python']
 
 desc "Build the html, xml, and diff coverage reports"
 task :coverage => :report_dirs do