fix typos, update link to 'Tidy First?'

Author: Xronophobe

chapter_12_organising_test_files.asciidoc

@@ -159,7 +159,7 @@ and wait until we're back to a fully passing test suite before refactoring.
 
 Kent Beck has a book-length exploration of the tradeoffs
 of refactor-now vs refactor-later, called
-https://learning.oreilly.com/library/view/tidy-first/9781098151232/[Tidy First?]
+https://www.oreilly.com/library/view/tidy-first/9781098151232/[Tidy First?]
 **********************************************************************
 
 
@@ -291,7 +291,7 @@ Some people like to use them a lot in Django code
 (e.g., your views might import models using `from .models import List`,
 instead of `from list.models`).
 Ultimately this is a matter of personal preference.
-I prefer to use relative imports only when I'm super-super
+I prefer to use relative imports only when I'm super-super confident
 that the relative position of the thing I'm importing won't change.
 That applies in this case because I know for sure
 all the tests will sit next to _base.py_, which they inherit from.
@@ -385,7 +385,7 @@ For now, let's commit!
 ----
 $ *git status*
 $ *git add src/functional_tests*
-$ *git commit -m "Moved Fts into their own individual files"*
+$ *git commit -m "Moved FTs into their own individual files"*
 ----
 
 Great.  We've split our functional tests nicely out into different files.
@@ -631,7 +631,7 @@ through what happened:
 <3> To explain where the exception has actually come from,
     the traceback takes us back into _test_list_item_validation.py_
     and inside the body of the `lambda` function,
-    and tells us that it the attempt to find the `.invalid-feedback` element
+    and tells us that the attempt to find the `.invalid-feedback` element
     that failed.