Consistently use 'relics' term instead of 'artifacts'

guidelines/hierarchy.md

 will most probably depend on the test framework you use.
 
 
-### artifacts ###
+### relics ###
 
 If your test suite creates files that you usually need to review,
 this is a good place.  Subdirectories here should bear a timestamp in
     ├── LICENSE             # \
     ├── Makefile            #  Pretty much standard files...
     ├── README.md           # /
-    ├── artifacts
-    │   ├── artifacts-inigrep_inigrep-20161202-073432
-    │   │   ├── TF_ENUMERATED_SUBTESTS
-    │   │   ├── TF_FILTERED_SUBTESTS
-    │   │   ├── TF_RUN
-    │   │   ├── oracle      # \
-    │   │   │   └── ...     #   artifacts are now huge since 
-    │   │   ├── result      #   I ran a lot of tests recently
-    │   │   │   └── ...     # /
-    │   │   └── test
-    │   │       └── ...
-    │   └── artifacts-shellfu_api-20161202-081440
-    │       └── ...
     ├── mkit.ini            # <- MKit meta-data file
     ├── notes               # <- my design notes, although
     │   └── style.md        #    most are still in my head :)
     │   │   ├── control     #   alpha RPMs and .deb's
     │   │   └── ...         #   (so far, probably for good)
     │   └── shellfu.spec    # /
+    ├── relics
+    │   ├── relics-inigrep_inigrep-20161202-073432
+    │   │   ├── TF_ENUMERATED_SUBTESTS
+    │   │   ├── TF_FILTERED_SUBTESTS
+    │   │   ├── TF_RUN
+    │   │   ├── oracle      # \
+    │   │   │   └── ...     #   relics are now huge since 
+    │   │   ├── result      #   I ran a lot of tests recently
+    │   │   │   └── ...     # /
+    │   │   └── test
+    │   │       └── ...
+    │   └── relics-shellfu_api-20161202-081440
+    │       └── ...
     ├── src
     │   ├── bin                     # \
     │   │   ├── shellfu-doc         #   here most of the "meat" lives,