Updates to 2018/ferguson

Format changes in the README.md.

Update the test.sh and test-strings.txt files: modify the goodbye
message in the script (for fun) and add some fun strings for it to
search out.

2018/ferguson/test-strings.txt

@@ -1,9 +1,17 @@
 YOU ARE LIKE A WEASEL
 YOU SMELL LIKE A WEASEL
+I SMELL LIKE A WEASEL
 YOU ARE A WEASEL
 I AM THE WEASEL
 I AM THE WALRUS
 YOU ARE THE WALRUS
 YOU ARE THE WEASEL
 PAULINE HANSEN ACTS LIKE A WEASEL
+METHINKS IT IS LIKE A WEASEL
+MONKEY SEE, MONKEY DO!
+STOP MONKEYING ABOUT!
+WHAT DO YOU MEAN I'M A MONKEY?!
+PROBLEM BETWEEN KEYBOARD AND CHAIR
+MY PRECIOUS. YES, MY PRECIOUS.
+MY PRECIOUS! O MY PRECIOUS!
 IOCCC BEST USE OF WEASEL WORDS