Pin ember-cli to 3.9 for node 6

package.json

@@ -39,17 +39,16 @@
     "broccoli-concat": "^3.7.4",
     "broccoli-funnel": "^2.0.2",
     "broccoli-merge-trees": "^2.0.0",
-    "broccoli-typescript-compiler": "^4.0.1",
-    "ember-cli": "^3.12.0",
+    "broccoli-typescript-compiler": "^4.1.0",
+    "ember-cli": "~3.9.0",
     "loader.js": "^4.7.0",
     "prettier": "1.18.2",
     "qunit": "^2.9.2",
     "route-recognizer": "^0.3.4",
     "rsvp": "^4.8.5",
     "tslint": "^5.20.0",
     "tslint-config-prettier": "^1.18.0",
-    "tslint-plugin-prettier": "^2.0.1",
-    "typescript": "~3.0.1"
+    "tslint-plugin-prettier": "^2.0.1"
   },
   "peerDependencies": {
     "route-recognizer": "^0.3.4",

yarn.lock

@@ -1462,18 +1462,18 @@ broccoli-stew@^2.1.0:
     symlink-or-copy "^1.2.0"
     walk-sync "^0.3.3"
 
-broccoli-typescript-compiler@^4.0.1:
-  version "4.0.1"
-  resolved "https://registry.yarnpkg.com/broccoli-typescript-compiler/-/broccoli-typescript-compiler-4.0.1.tgz#7a03e003b3032acf9a2feaae973ae2e257393d04"
-  integrity sha512-3psnblHnaMTfh3sE9lkLTKs8XjK563vbKMh/1mslmabqt9wuAOfTMUNEMbmGCofVoMUd9C/ydrmN5eZ6mJUNpQ==
+broccoli-typescript-compiler@^4.1.0:
+  version "4.1.0"
+  resolved "https://registry.yarnpkg.com/broccoli-typescript-compiler/-/broccoli-typescript-compiler-4.1.0.tgz#8511b73a7b019f6b6267679df64e211ca65ba036"
+  integrity sha512-pz+hQMlfwvklezPB1K4COYdf5SIQX6Dl4bdLX/R0uTNEJAwVa3Is/4YSXXm2L+LQdfMCZSXzqjbC5AGgvdbB6A==
   dependencies:
     broccoli-funnel "^2.0.1"
     broccoli-merge-trees "^3.0.0"
     broccoli-plugin "^1.3.0"
     fs-tree-diff "^0.5.7"
     heimdalljs "0.3.3"
     md5-hex "^2.0.0"
-    typescript "~3.0.1"
+    typescript "~3.2.1"
     walk-sync "^0.3.2"
 
 broccoli@^3.1.1:
@@ -6032,10 +6032,10 @@ type-is@~1.6.17, type-is@~1.6.18:
     media-typer "0.3.0"
     mime-types "~2.1.24"
 
-typescript@~3.0.1:
-  version "3.0.1"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.0.1.tgz#43738f29585d3a87575520a4b93ab6026ef11fdb"
-  integrity sha512-zQIMOmC+372pC/CCVLqnQ0zSBiY7HHodU7mpQdjiZddek4GMj31I3dUJ7gAs9o65X7mnRma6OokOkc6f9jjfBg==
+typescript@~3.2.1:
+  version "3.2.4"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.2.4.tgz#c585cb952912263d915b462726ce244ba510ef3d"
+  integrity sha512-0RNDbSdEokBeEAkgNbxJ+BLwSManFy9TeXz8uW+48j/xhEXv1ePME60olyzw2XzUqUBNAYFeJadIqAgNqIACwg==
 
 uc.micro@^1.0.1, uc.micro@^1.0.3:
   version "1.0.3"