Travis: install libmicrohttpd

For the write_prometheus plugin

diff --git a/.travis.yml b/.travis.yml
index 73d0153..fc250cb 100644 (file)
--- a/.travis.yml
+++ b/.travis.yml
@@ -24,6 +24,7 @@ before_install:
       liblua5.2-dev
       liblvm2-dev
       libmemcached-dev
+      libmicrohttpd-dev
       libmnl-dev
       libmodbus-dev
       libmosquitto0-dev