Update sqlstring to 2.3.1

Author: dougwilson

Changes.md

@@ -9,6 +9,8 @@ you spot any mistakes.
 * Include connection ID in debug output
 * Update `bignumber.js` to 4.1.0
 * Update `readable-stream` to 2.3.4
+* Update `sqlstring` to 2.3.1
+  - Fix incorrectly replacing non-placeholders in SQL
 
 ## v2.15.0 (2017-10-05)
 

package.json

@@ -16,7 +16,7 @@
     "bignumber.js": "4.1.0",
     "readable-stream": "2.3.4",
     "safe-buffer": "5.1.1",
-    "sqlstring": "2.3.0"
+    "sqlstring": "2.3.1"
   },
   "devDependencies": {
     "after": "0.8.2",