travis-build: check code formatting during the build

extra/travis-build

@@ -39,7 +39,8 @@ deps_fedora() {
         at-spi2-core-devel \
         gtk3-devel \
         glib-networking \
-        tree
+        tree \
+        uncrustify
 }
 
 deps_opensuse() {
@@ -57,7 +58,8 @@ deps_opensuse() {
            at-spi2-core-devel \
            gtk3-devel \
            glib-networking \
-           tree
+           tree \
+           uncrustify
 }
 
 deps_archlinux() {
@@ -76,7 +78,8 @@ deps_archlinux() {
            gtk3 \
            gnutls \
            glib-networking \
-           tree
+           tree \
+           uncrustify
 }
 
 deps_ubuntu_xenial() {
@@ -92,7 +95,8 @@ deps_ubuntu_xenial() {
                 libnotify-dev \
                 libgtk-3-dev \
                 glib-networking \
-                tree
+                tree \
+                uncrustify
 }
 
 install_deps() {
@@ -117,7 +121,8 @@ install_deps() {
 
 build() {
     set -ex
-    mkdir build && \
+    ./extra/fmt check && \
+        mkdir build && \
         cd build && \
         meson .. && \
         ninja && \