Update tests from snakemake#823 MREs

- Can't have the b.txt in first text be temp and expect it present, it
will correctly be deleted.
- Add third MRE which is targeting more of a log issue

tests/test_issue823_1/Snakefile

@@ -21,7 +21,7 @@ rule b:
     input:
         _checkpoint_output,
     output:
-        temp('b.txt')
+        'b.txt'
     shell:
         "touch {output}"
 

tests/test_issue823_3/Snakefile

@@ -0,0 +1,9 @@
+rule all:
+    input:
+        "a.txt"
+
+checkpoint a:
+    output:
+        "a.txt"
+    shell:
+        "touch {output}"

tests/tests.py

@@ -798,11 +798,18 @@ def test_issue805():
     run(dpath("test_issue805"), shouldfail=True)
 
 
-def test_issue823():
+def test_issue823_1():
     run(dpath("test_issue823_1"))
+
+
+def test_issue823_2():
     run(dpath("test_issue823_2"))
 
 
+def test_issue823_3():
+    run(dpath("test_issue823_3s"))
+
+
 @skip_on_windows
 def test_pathlib():
     run(dpath("test_pathlib"))