travis-fix: make sure psql is using the environment's perl

psql was using /usr/bin/perl which is 5.14 even in the 5.10 test
environment. This should force psql to always follow the environment

.travis.yml

@@ -13,6 +13,7 @@ before_install:
     - sudo apt-get -y install unzip
     - wget https://github.com/bioperl/bioperl-live/archive/bioperl-release-1-2-3.zip
     - unzip bioperl-release-1-2-3.zip
+    - sudo sed -i '1s/usr\/bin\/perl -w/usr\/bin\/env perl/' `which psql`
 
 
 install: