Increased line length limit to 160 characters

Change-Id: I038529ec79305ed6790dc9d74c206ba489883bfb
diff --git a/Makefile b/Makefile
index 170c6ee..0da130b 100644
--- a/Makefile
+++ b/Makefile
@@ -38,7 +38,7 @@
 rst-lint: doc_venv
 	source ./doc_venv/bin/activate ;\
 	set -u ;\
-	doc8 --ignore-path doc_venv --ignore-path _build $(SOURCEDIR)
+	doc8 --ignore-path doc_venv --ignore-path _build --max-line-length 160 $(SOURCEDIR)
 
 # clean up
 clean: