docs: also paver test no longer exists, remove it

paver for js test is discussed below separately

python testing is covered well in the next section, running all python
tests is not useful for development loops

docs/concepts/testing/testing.rst

@@ -85,16 +85,6 @@ Running Tests
 
 **Unless otherwise mentioned, all the following commands should be run from inside the lms docker container.**
 
-You can run all of the unit-level tests using this command::
-
-    paver test
-
-This includes python, JavaScript, and documentation tests.
-
-Note -
-`paver` is a scripting tool. To get information about various options, you can run the this command::
-
-    paver -h
 
 Running Python Unit tests
 -------------------------
@@ -106,8 +96,8 @@ Pytest (and all of the plugins we use with it) has a lot of options. Use `pytest
 .. _pytest: https://pytest.org/
 
 
-Running a Single Test
-~~~~~~~~~~~~~~~~~~~~~
+Running Python Test Subsets
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 When developing tests, it is often helpful to be able to really just run one single test without the overhead of PIP installs, UX builds, etc.