changed install script and docs to use postfix instead of sendmail

doc/debian_ubuntu.sh

@@ -3,7 +3,7 @@
 sudo apt-get update
 sudo apt-get upgrade
 
-sudo apt-get install -y git git-core wget curl gcc checkinstall libxml2-dev libxslt-dev sqlite3 libsqlite3-dev libcurl4-openssl-dev libreadline-gplv2-dev libc6-dev libssl-dev libmysql++-dev make build-essential zlib1g-dev libicu-dev redis-server openssh-server python-dev python-pip libyaml-dev sendmail
+sudo apt-get install -y git git-core wget curl gcc checkinstall libxml2-dev libxslt-dev sqlite3 libsqlite3-dev libcurl4-openssl-dev libreadline-gplv2-dev libc6-dev libssl-dev libmysql++-dev make build-essential zlib1g-dev libicu-dev redis-server openssh-server python-dev python-pip libyaml-dev postfix
 
 wget http://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.3-p194.tar.gz
 tar xfvz ruby-1.9.3-p194.tar.gz

doc/installation.md

@@ -60,7 +60,7 @@ Also read the [Read this before you submit an issue](https://github.com/gitlabhq
     sudo apt-get update
     sudo apt-get upgrade
 
-    sudo apt-get install -y wget curl gcc checkinstall libxml2-dev libxslt-dev sqlite3 libsqlite3-dev libcurl4-openssl-dev libreadline6-dev libc6-dev libssl-dev libmysql++-dev make build-essential zlib1g-dev libicu-dev redis-server openssh-server git-core python-dev python-pip libyaml-dev sendmail
+    sudo apt-get install -y wget curl gcc checkinstall libxml2-dev libxslt-dev sqlite3 libsqlite3-dev libcurl4-openssl-dev libreadline6-dev libc6-dev libssl-dev libmysql++-dev make build-essential zlib1g-dev libicu-dev redis-server openssh-server git-core python-dev python-pip libyaml-dev postfix
     
     # If you want to use MySQL:
     sudo apt-get install -y mysql-server mysql-client libmysqlclient-dev