Fix path to boulder_dem.py file

The directory changed from `se` to `best-practices`.

lessons/git/git-collaborative-project.md

@@ -123,7 +123,7 @@ however, this time we'll do so in your fork of the ESPIn repository.
 
 Use your text editor to open the Python script:
 ```
-$ nano ./lessons/se/boulder_dem.py
+$ nano ./lessons/best-practices/boulder_dem.py
 ```
 and recall that we'd like to change the colormap from "jet" to "viridis"
 on line 21 of the file, like so:
@@ -140,15 +140,15 @@ Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
   (use "git checkout -- <file>..." to discard changes in working directory)
 
-	modified:   lessons/se/boulder_dem.py
+	modified:   lessons/best-practices/boulder_dem.py
 
 no changes added to commit (use "git add" and/or "git commit -a")
 ```
 
 Commit the change to the branch
 (noting that we're again skipping the staging step):
 ```
-$ git commit lessons/se/boulder_dem.py -m "Use viridis colormap for display"
+$ git commit lessons/best-practices/boulder_dem.py -m "Use viridis colormap for display"
 [mdpiper/change-colormap 5b0d87c] Use viridis colormap for display
  1 file changed, 1 insertion(+), 1 deletion(-)
 ```

lessons/git/git-single-user-project.md

@@ -72,12 +72,12 @@ we downloaded the [ESPIn repository](https://github.com/csdms/espin)
 as a zip archive and uncompressed it in our **Desktop** directory.
 Copy the file **boulder_dem.py** from there to the current directory.
 ```
-$ cp ~/Desktop/espin-main/lessons/se/boulder_dem.py .
+$ cp ~/Desktop/espin-main/lessons/best-practices/boulder_dem.py .
 ```
 Alternately,
 we could download the file directly from GitHub with `curl`:
 ```
-$ curl https://raw.githubusercontent.com/csdms/espin/main/lessons/se/boulder_dem.py > boulder_dem.py 
+$ curl https://raw.githububest-practicesrcontent.com/csdms/espin/main/lessons/best-practices/boulder_dem.py > boulder_dem.py 
 ```
 In either case,
 check that the file is now present: