Add consistency check for dependencies listed in README.md and doc/INSTALL.md

Makefile

@@ -220,7 +220,10 @@ check-whitespace/%: %
 
 check-whitespace: check-whitespace/Makefile check-whitespace/tools/check-bolt.c $(ALL_TEST_PROGRAMS:%=check-whitespace/%.c)
 
-check-source: check-makefile check-source-bolt check-whitespace
+check-markdown:
+	@tools/check-markdown.sh
+
+check-source: check-makefile check-source-bolt check-whitespace check-markdown
 
 full-check: check check-source
 

tools/check-markdown.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+diff -u <(egrep 'sudo apt-get install .*git' README.md) \
+     <(egrep 'sudo apt-get install .*git' doc/INSTALL.md)
+if [[ $? != 0 ]]; then
+    echo "Dependencies listed in README.md are not identical to those listed in doc/INSTALL.md (see above). Please fix."
+    exit 1
+fi