updating supported browsers

Author: lmccart

developer_docs/supported_browsers.md

@@ -4,29 +4,27 @@
 
 ## Our stated goal:
 
-We support the current version of the browser, plus the previous major release of the browser.
+We support the current version of the browser, plus the previous major release of the browser. Exceptions: Internet Explorer, which has not had a new major release since 2013, we support only the most recent major release (v.11); Safari, which has not had a new major release since 2015, we support only the most recent major release (v.11)
 
 ## Potential issues:
 
-* We are using webGL, which has limited support in IE 10, firefox, and the Android browser.
+* We are using webGL, which has limited support in IE 10, Firefox, and the Android browser.
 * We are using typed arrays, which does not have support for Uint8ClampedArray in IE 10 and IE Mobile 10/11.
 * Canvas blend modes are not supported in IE.
 * WebAudio is not supported in IE or the Android Browser.
 
 
-As of August 2016, this means that we support:
+As of September 2018, this means that we support:
 
 |Browser            |  Current Version  | Previous Version|  Notes                    
 |-------------------|------------------:|----------------:|--------------
-|Internet Explorer  |             v. 11 |  v. 10          | Needs a polyfill for Uint8ClampedArray.  <br> No support for WebAudio. 
-|IE Mobile          |             v. 11 |  v.10           | v.10 does not fully support webGL.<br>Needs a polyfill for Uint8ClampedArray.   <br> No support for WebAudio.
-|Microsoft Edge     |             v. 25 |  v. 23          |
-|Chrome             |             v. 52 |  v. 51          |
-|Chrome for Android |             v. 40 |                 | Not sure if previous versions exist
-|Firefox            |             v. 47 |  v. 36          | 
-|Safari             |             v. 9  |  v. 8           |
-|iOS Safari         |             v. 9  |  v. 8           |
-|Android Browser    |             v. 40 |  v. 4.4.4       | Does not support webGL.  <br> No support for WebAudio.
-|Opera              |             v. 39 |  v. 38          |
-
-We will try to list all known problems across the different browsers here but for a complete list of supported feature on a browser visit [caniuse.com](http://caniuse.com) and search for specific features (ie. [Webgl](http://caniuse.com/#search=webgl))
+|Internet Explorer  |             v. 11 |  Not supported  | No support for WebAudio
+|Microsoft Edge     |             v. 42 |  v. 41          |
+|Chrome             |             v. 68 |  v. 67          |
+|Chrome for Android |             v. 68 |  v. 67          |
+|Firefox            |             v. 61 |  v. 60          | 
+|Safari             |             v. 11 |  Not supported  |
+|iOS Safari         |           v. 11.4 |  v. 11.2        |
+|Opera              |             v. 54 |  v. 53          |
+
+We will try to list all known problems across the different browsers here but for a complete list of supported feature on a browser visit [caniuse.com](http://caniuse.com) and search for specific features (ie. [WebGL](http://caniuse.com/#search=webgl))