Fail build on errors

.ci/coverage.sh

 #!/bin/bash
 
+set -ex
+
 cd build/
 
 # Capture coverage info.

.ci/script.sh

 #!/bin/bash
 
+set -ex
+
 if [ $TRAVIS_OS_NAME == linux ]; then
     sudo update-alternatives --remove-all gcc
     sudo update-alternatives --remove-all g++

lib/crypto/client.cpp

@@ -3,6 +3,8 @@
 #include "mtxclient/crypto/client.hpp"
 #include "mtxclient/crypto/types.hpp"
 
+#include "sodium.h"
+
 using json = nlohmann::json;
 using namespace mtx::crypto;