maint: fetch tags on Travis before running the build

Signed-off-by: Yury V. Zaytsev <yury@shurup.com>

.travis.yml

@@ -10,6 +10,9 @@ install:
   - sudo apt-get install -y e2fslibs-dev libaspell-dev libglib2.0-dev libgpm-dev libncurses5-dev libslang2-dev libssh2-1-dev libx11-dev unzip
   - sudo apt-get install -y wget exuberant-ctags python-pygments ruby
 
+before_script:
+  - git fetch --tags
+
 script:
   - ./maint/utils/check-indent.sh
   - ./autogen.sh