Add entry for unittest documentation.
diff --git a/Doc/lib/lib.tex b/Doc/lib/lib.tex
index e74329b..3e8cab1 100644
--- a/Doc/lib/lib.tex
+++ b/Doc/lib/lib.tex
@@ -112,6 +112,7 @@
 
 \input{libmisc}                 % Miscellaneous Services
 \input{libdoctest}
+\input{libunittest}
 \input{libmath}
 \input{libcmath}
 \input{librandom}