Adapt travis to run Tmux 2.5 tests

Author: thalesmello

.travis.yml

@@ -1,14 +1,24 @@
 # generic packages
 before_install:
   - sudo apt-get update
-  - sudo apt-get install -y git-core expect
+  - sudo apt-get install -y git-core expect gawk
   - sudo apt-get install -y python-software-properties software-properties-common
 
-# install latest Tmux 1.9a
+# install Tmux 2.5
 install:
-  - sudo add-apt-repository -y ppa:pi-rho/dev
-  - sudo apt-get update
-  - sudo apt-get install -y tmux=1.9a-1~ppa1~p
+  - VERSION=2.5
+  - sudo apt-get -y remove tmux
+  - sudo apt-get -y install wget tar libevent-dev libncurses-dev make
+  - wget https://github.com/tmux/tmux/releases/download/${VERSION}/tmux-${VERSION}.tar.gz
+  - tar xf tmux-${VERSION}.tar.gz
+  - rm -f tmux-${VERSION}.tar.gz
+  - cd tmux-${VERSION}
+  - ./configure
+  - make
+  - sudo make install
+  - cd -
+  - sudo rm -rf /usr/local/src/tmux-*
+  - sudo mv tmux-${VERSION} /usr/local/src
 
 # override PS1 and irb prompt, fetch a git repo used for testing
 before_script: