Add libffi to requirements

diff --git a/INSTALL.md b/INSTALL.md
index 7571cff50fd7c7eb6d3b79e4f59f713aefb794ed..768cbd540c430a3d998ed40fca36052f2dd4ed84 100644 (file)
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -32,7 +32,7 @@ sudo apt-get install ruby2.3 libruby2.3 ruby2.3-dev \
                      libmagickwand-dev libxml2-dev libxslt1-dev nodejs \
                      apache2 apache2-dev build-essential git-core \
                      postgresql postgresql-contrib libpq-dev postgresql-server-dev-all \
-                     libsasl2-dev imagemagick
+                     libsasl2-dev imagemagick libffi-dev
 sudo gem2.3 install bundler
 ```
 
@@ -47,7 +47,7 @@ sudo yum install ruby ruby-devel rubygem-rdoc rubygem-bundler rubygems \
                  libxml2-devel js \
                  gcc gcc-c++ git \
                  postgresql postgresql-server postgresql-contrib postgresql-devel \
-                 perl-podlators ImageMagick
+                 perl-podlators ImageMagick libffi-devel
 ```
 
 If you didn't already have PostgreSQL installed then create a PostgreSQL instance and start the server: