Update scripts for travis-ci

.travis.yml

@@ -1,7 +1,15 @@
+sudo: true
 language: c
 compiler:
     - gcc
     - clang
+before_install:
+    - git clone https://github.com/jedisct1/libsodium
+    - pushd libsodium
+    - ./autogen.sh
+    - ./configure && make
+    - sudo make install
+    - popd
 addons:
     apt:
         packages:
@@ -9,7 +17,6 @@ addons:
             - autotools-dev
             - libudns-dev
             - libev-dev
-            - libsodium-dev
             - asciidoc
             - xmlto
 script: