Cleans up functional test README

Mostly correcting a typo in the `instance_information.json` config
filename, but also updated some of the example commands. The notes
regarding potentially failing tests also seemed out of date, as several
members of the team have confirmed working functional tests under the
new TB Selenium logic recently.

securedrop/tests/functional/README.md

@@ -5,7 +5,7 @@
 - `./manage.py reset`    # This will clean the DB for testing
 - `./create-demo-user.py`  
 
-Update this information to the `tests/functional/instance_infomration.json file.
+Update this information to the `tests/functional/instance_information.json file.
 
 The content of the file looks like below.
 
@@ -25,14 +25,9 @@ The content of the file looks like below.
 
 ### Run the tests
 
-Go inside of the securedrop directory.
-
 ```
-$ ./bin/dev-shell ./bin/run-test --capture=no -v tests/functional/test_source_not_found.py
+cd securedrop
+./bin/dev-shell ./bin/run-test -v tests/functional/
 ```
-
-Remember to use to pipe to less, or less in case of a failure, there will be too much output.
-
-- `functional/test_source_warnings.py`: THis will fail as we are actually using Tor Browser :)
-- `functional/test_submission_not_in_memory.py`: Not inside of the server, so does not make sense.
-- `functional/test_source_session_timeout.py`: Remember to change the session time in the server to 0.02 before testing this.
+You may wish to append a pipe to less (i.e. `| less`), as a failure may generate
+many pages of output, making it difficult to scroll back.