[ci skip] Prepare 3.1.5 release
diff --git a/composer.json b/composer.json
index 0a898d2..c40d549 100644
--- a/composer.json
+++ b/composer.json
@@ -11,7 +11,7 @@
 		"source": "https://github.com/bcit-ci/CodeIgniter"
 	},
 	"require": {
-		"php": ">=5.2.4"
+		"php": ">=5.3.7"
 	},
 	"suggest": {
 		"paragonie/random_compat": "Provides better randomness in PHP 5.x"
diff --git a/system/core/CodeIgniter.php b/system/core/CodeIgniter.php
index 0fab092..823e034 100644
--- a/system/core/CodeIgniter.php
+++ b/system/core/CodeIgniter.php
@@ -55,7 +55,7 @@
  * @var	string
  *
  */
-	const CI_VERSION = '3.1.5-dev';
+	const CI_VERSION = '3.1.5';
 
 /*
  * ------------------------------------------------------
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 4695edc..21a1c0c 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -5,7 +5,7 @@
 Version 3.1.5
 =============
 
-Release Date: Not Released
+Release Date: Jun 19, 2017
 
 -  **Security**
 
@@ -28,7 +28,7 @@
 Version 3.1.4
 =============
 
-Release Date: March 20, 2017
+Release Date: Mar 20, 2017
 
 -  **Security**
 
diff --git a/user_guide_src/source/conf.py b/user_guide_src/source/conf.py
index f3d4775..c233b3a 100644
--- a/user_guide_src/source/conf.py
+++ b/user_guide_src/source/conf.py
@@ -48,9 +48,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = '3.1.5-dev'
+version = '3.1.5'
 # The full version, including alpha/beta/rc tags.
-release = '3.1.5-dev'
+release = '3.1.5'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/user_guide_src/source/installation/downloads.rst b/user_guide_src/source/installation/downloads.rst
index fd4f907..4cd824f 100644
--- a/user_guide_src/source/installation/downloads.rst
+++ b/user_guide_src/source/installation/downloads.rst
@@ -2,7 +2,7 @@
 Downloading CodeIgniter
 #######################
 
--  `CodeIgniter v3.1.5-dev (Current version) <https://codeload.github.com/bcit-ci/CodeIgniter/zip/3.1-stable>`_
+-  `CodeIgniter v3.1.5 (Current version) <https://codeload.github.com/bcit-ci/CodeIgniter/zip/3.1.5>`_
 -  `CodeIgniter v3.1.4 <https://codeload.github.com/bcit-ci/CodeIgniter/zip/3.1.4>`_
 -  `CodeIgniter v3.1.3 <https://codeload.github.com/bcit-ci/CodeIgniter/zip/3.1.3>`_
 -  `CodeIgniter v3.1.2 <https://codeload.github.com/bcit-ci/CodeIgniter/zip/3.1.2>`_