Run pip install to install the dependencies

Id2e8590193fbf21a52a767323a77df9be4048b5a requires
gerrit-dash-creator to be installed on the host where
reviewday runs. This patch runs pip install to install
all the dependencies.

Change-Id: I42ea25bdf69a1d75db24785db0e86396206fd48d

manifests/init.pp

@@ -15,14 +15,7 @@
 # Class: reviewday
 #
 class reviewday {
-  if ! defined(Package['python-launchpadlib']) {
-    package { 'python-launchpadlib':
-      ensure => present,
-    }
-  }
-  package { 'python-cheetah':
-    ensure => present,
-  }
+
 
   file {'/var/lib/reviewday':
     ensure  => directory,

manifests/site.pp

@@ -82,6 +82,13 @@ define reviewday::site(
     revision => 'master',
   }
 
+  exec { 'install-reviewday-dependencies':
+    command   => 'pip install -r requirements.txt',
+    path      => '/var/lib/reviewday/reviewday',
+    subscribe => Vcsrepo['/var/lib/reviewday/reviewday'],
+    require   => Class['pip'],
+  }
+
   file { $httproot:
     ensure => directory,
     owner  => 'reviewday',
@@ -101,6 +108,7 @@ define reviewday::site(
     command => "cd /var/lib/reviewday/reviewday && PYTHONPATH=\$PWD flock -n /var/lib/reviewday/update.lock python bin/reviewday -o ${httproot}",
     minute  => '*/30',
     user    => 'reviewday',
+    require => Exec['install-reviewday-dependencies'],
   }
 
 }