Change Postgres version 10 to 9.5 in docs/ and README.md because Ubuntu 16.04 ships with v9.5

https://meta.discourse.org/t/postgres-minimum-version/98354

README.md

@@ -26,7 +26,7 @@ Browse [lots more notable Discourse instances](https://www.discourse.org/custome
 
 2. If you're familiar with how Rails works and are comfortable setting up your own environment, use our [**Discourse Advanced Developer Guide**](docs/DEVELOPER-ADVANCED.md).
 
-Before you get started, ensure you have the following minimum versions: [Ruby 2.4+](http://www.ruby-lang.org/en/downloads/), [PostgreSQL 10+](http://www.postgresql.org/download/), [Redis 2.6+](http://redis.io/download). If you're having trouble, please see our [**TROUBLESHOOTING GUIDE**](docs/TROUBLESHOOTING.md) first!
+Before you get started, ensure you have the following minimum versions: [Ruby 2.4+](http://www.ruby-lang.org/en/downloads/), [PostgreSQL 9.5+](http://www.postgresql.org/download/), [Redis 2.6+](http://redis.io/download). If you're having trouble, please see our [**TROUBLESHOOTING GUIDE**](docs/TROUBLESHOOTING.md) first!
 
 ## Setting up Discourse
 

docs/DEVELOPER-ADVANCED.md

@@ -12,7 +12,7 @@ To get your Ubuntu 16.04 LTS install up and running to develop Discourse and Dis
     whoami > /tmp/username
     sudo add-apt-repository ppa:chris-lea/redis-server
     sudo apt-get -yqq update
-    sudo apt-get -yqq install python-software-properties vim curl expect debconf-utils git-core build-essential zlib1g-dev libssl-dev openssl libcurl4-openssl-dev libreadline6-dev libpcre3 libpcre3-dev imagemagick postgresql postgresql-contrib-10 libpq-dev postgresql-server-dev-10 redis-server advancecomp gifsicle jhead jpegoptim libjpeg-turbo-progs optipng pngcrush pngquant gnupg2
+    sudo apt-get -yqq install python-software-properties vim curl expect debconf-utils git-core build-essential zlib1g-dev libssl-dev openssl libcurl4-openssl-dev libreadline6-dev libpcre3 libpcre3-dev imagemagick postgresql postgresql-contrib-9.5 libpq-dev postgresql-server-dev-9.5 redis-server advancecomp gifsicle jhead jpegoptim libjpeg-turbo-progs optipng pngcrush pngquant gnupg2
 
     # Ruby
     curl -sSL https://rvm.io/mpapis.asc | gpg2 --import -

docs/DEVELOPMENT-OSX-NATIVE.md

@@ -96,9 +96,9 @@ You should now be able to check out a clone of Discourse.
 
 Atlassian has a free Git client for OS X called [SourceTree](http://www.sourcetreeapp.com/download/) which can be extremely useful for keeping visual track of what's going on in Git-land. While it's arguably not a full substitute for command-line git (especially if you know the command line well), it's extremely powerful for a GUI version-control client.
 
-## Postgres 10
+## Postgres 9.5
 
-OS X might ship with Postgres 9.x, but you're better off going with Postgres 10+ from Homebrew or [Postgres.app](http://postgresapp.com).
+OS X might ship with Postgres 9.1.5, but you're better off going with 9.5 and above from Homebrew or [Postgres.app](http://postgresapp.com).
 
 ### Using Postgres.app
 

docs/INSTALL.md

@@ -21,7 +21,7 @@ Hosting Rails applications is complicated. Even if you already have Postgres, Re
 
 ### Software Requirements
 
-- [Postgres 10+](http://www.postgresql.org/download/)
+- [Postgres 9.5+](http://www.postgresql.org/download/)
 - [Redis 2.6+](http://redis.io/download)
 - [Ruby 2.4+](http://www.ruby-lang.org/en/downloads/) (we recommend 2.4.4 or higher)
 

docs/TROUBLESHOOTING.md

@@ -10,7 +10,7 @@ reaching out to the community for help:
    `ruby -v` and checking the response.
 
 
-2. Are you on Postgres 10 or later with HSTORE enabled?
+2. Are you on Postgres 9.5 or later with HSTORE enabled?
 
    You can check your postgres version by typing `psql --version`. To see if hstore is
    installed, open a session to postgres and type `\dx` and see if hstore is listed.