feat(all): Add set -xe option to build scripts

.build-scripts/codecov.sh

@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -xe
+
 wget https://github.com/SimonKagstrom/kcov/archive/master.tar.gz
 tar xzf master.tar.gz
 cd kcov-master

.build-scripts/site-upload.sh

@@ -1,7 +1,10 @@
 #!/bin/bash
 
+set -xe
+
 cd website
 make clean && make
+echo "lettre.at" > _book/CNAME
 sudo pip install ghp-import
 ghp-import -n _book
-git push -fq https://${GH_TOKEN}@github.com/${TRAVIS_REPO_SLUG}.git gh-pages
+git push -f https://${GH_TOKEN}@github.com/${TRAVIS_REPO_SLUG}.git gh-pages