Merge #27

27: run linkchecker simulating the bookshelf layout r=japaric a=japaric

this catches / prevents build errors in the bookshelf repo like
https://travis-ci.org/rust-embedded/bookshelf/builds/433522599

Co-authored-by: Jorge Aparicio <jorge@japaric.io>

Author: bors[bot]

ci/script.sh

@@ -6,6 +6,15 @@ main() {
 
     linkchecker book
 
+    # now check this as a directory of the bookshelf
+    rm -rf shelf
+    mkdir shelf
+    mv book shelf
+    linkchecker shelf
+
+    mv shelf/book .
+    rmdir shelf
+
     # test the instructions at different stages
     cd ci