devkit: Release 0.8.0

Is amber/Platform aware and loads compiler via amber/lang.
Accepts any decent (>=2) es6-promise version.

external/amber-dev/package.json

@@ -1,6 +1,6 @@
 {
   "name": "amber-dev",
-  "version": "0.7.1",
+  "version": "0.8.0",
   "description": "Development goodies for Amber Smalltalk",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
@@ -20,7 +20,7 @@
   "dependencies": {
     "amd-config-builder": "^0.2.0",
     "amdefine": ">=0.1.1",
-    "es6-promise": "^2.0.0",
+    "es6-promise": ">=2.0.0",
     "requirejs": "^2.1.19",
     "requirejs-text": "^2.0.12"
   }