chore(deps): upgrade ember-fetch@^6.2.0

This upgrades ember-fetch to `^6.2.0`. The primary reason for upgrading are the fixes for:

- Usage of ember-fetch in monorepos:
  ember-cli/ember-fetch#165
  https://github.com/ember-cli/ember-fetch/releases/tag/v6.1.1

- Enabling Fastboot relative URLs:
  ember-cli/ember-fetch#143
  https://github.com/ember-cli/ember-fetch/releases/tag/v6.2.0

package.json

@@ -48,7 +48,7 @@
     "ember-component-css": "0.6.5",
     "ember-concurrency": "^0.8.21",
     "ember-data": "2.x - 3.x",
-    "ember-fetch": "^5.1.3",
+    "ember-fetch": "^6.2.0",
     "ember-fetch-adapter": "^0.4.3",
     "ember-href-to": "^1.15.1",
     "ember-keyboard": "^4.0.0",

yarn.lock

@@ -761,11 +761,6 @@
   resolved "https://registry.yarnpkg.com/@types/node/-/node-9.6.32.tgz#1b64134f630b30c9cda4810aa4a94fc2d4141dbd"
   integrity sha512-5+L3wQ+FHoQ589EaH6rYICleuj8gnunq+1CJkM9fxklirErIOv+kxm3s/vecYnpJOYnFowE5uUizcb3hgjHUug==
 
-"@xg-wang/whatwg-fetch@^3.0.0":
-  version "3.0.0"
-  resolved "https://registry.yarnpkg.com/@xg-wang/whatwg-fetch/-/whatwg-fetch-3.0.0.tgz#f7b222c012a238e7d6e89ed3d72a1e0edb58453d"
-  integrity sha512-ULtqA6L75RLzTNW68IiOja0XYv4Ebc3OGMzfia1xxSEMpD0mk/pMvkQX0vbCFyQmKc5xGp80Ms2WiSlXLh8hbA==
-
 abab@^1.0.0:
   version "1.0.4"
   resolved "https://registry.yarnpkg.com/abab/-/abab-1.0.4.tgz#5faad9c2c07f60dd76770f71cf025b62a63cfd4e"
@@ -1174,7 +1169,7 @@ babel-code-frame@^6.22.0, babel-code-frame@^6.26.0:
     esutils "^2.0.2"
     js-tokens "^3.0.2"
 
-babel-core@^6.24.1, babel-core@^6.26.0, babel-core@^6.26.3:
+babel-core@^6.24.1, babel-core@^6.26.0:
   version "6.26.3"
   resolved "https://registry.yarnpkg.com/babel-core/-/babel-core-6.26.3.tgz#b2e2f09e342d0f0c88e2f02e067794125e75c207"
   integrity sha512-6jyFLuDmeidKmUEb3NM+/yawG0M2bDZ9Z1qbZP59cyHLz8kYGKYwpJP0UwUKKUiTRNvxfLesJnTedqczP7cTDA==
@@ -4443,23 +4438,21 @@ ember-fetch-adapter@^0.4.3:
   dependencies:
     ember-cli-babel "^6.12.0"
 
-ember-fetch@^5.1.3:
-  version "5.1.3"
-  resolved "https://registry.yarnpkg.com/ember-fetch/-/ember-fetch-5.1.3.tgz#f649c60d523bf1949125a4c497751df3b0c9f587"
-  integrity sha512-eQX54LpaQCS7IDuASNxArTVwkXIuwL9W4UZOLPyfEQJfmXd4IEx3mqoVlydBJJp2kjpuUZ1Wbd1XKC96ggY5gw==
+ember-fetch@^6.2.0:
+  version "6.2.0"
+  resolved "https://registry.yarnpkg.com/ember-fetch/-/ember-fetch-6.2.0.tgz#88988e1fb94f44722a1cbb9416310711e65f6706"
+  integrity sha512-Rc/QgsfPOldT55WSnlN4z7TqKsE1YqGnjAwB7I8myjgEulIu00t0wx4zLjznEz5ng6VeRupXW6WaGE/B/0BYUA==
   dependencies:
-    "@xg-wang/whatwg-fetch" "^3.0.0"
     abortcontroller-polyfill "^1.1.9"
-    babel-core "^6.26.3"
-    babel-preset-env "^1.7.0"
     broccoli-concat "^3.2.2"
+    broccoli-debug "^0.6.5"
     broccoli-merge-trees "^3.0.0"
     broccoli-rollup "^2.1.1"
     broccoli-stew "^2.0.0"
     broccoli-templater "^2.0.1"
     ember-cli-babel "^6.8.2"
-    node-fetch "^2.0.0-alpha.9"
-    rollup-plugin-babel "^3.0.7"
+    node-fetch "^2.3.0"
+    whatwg-fetch "^3.0.0"
 
 ember-get-config@^0.2.2:
   version "0.2.4"
@@ -5065,11 +5058,6 @@ estraverse@^4.0.0, estraverse@^4.1.0, estraverse@^4.1.1, estraverse@^4.2.0:
   resolved "https://registry.yarnpkg.com/estraverse/-/estraverse-4.2.0.tgz#0dee3fed31fcd469618ce7342099fc1afa0bdb13"
   integrity sha1-De4/7TH81GlhjOc0IJn8GvoL2xM=
 
-estree-walker@^0.2.1:
-  version "0.2.1"
-  resolved "https://registry.yarnpkg.com/estree-walker/-/estree-walker-0.2.1.tgz#bdafe8095383d8414d5dc2ecf4c9173b6db9412e"
-  integrity sha1-va/oCVOD2EFNXcLs9MkXO225QS4=
-
 estree-walker@^0.5.0, estree-walker@^0.5.2:
   version "0.5.2"
   resolved "https://registry.yarnpkg.com/estree-walker/-/estree-walker-0.5.2.tgz#d3850be7529c9580d815600b53126515e146dd39"
@@ -8191,10 +8179,10 @@ no-case@^2.2.0:
   dependencies:
     lower-case "^1.1.1"
 
-node-fetch@^2.0.0-alpha.9:
-  version "2.2.0"
-  resolved "https://registry.yarnpkg.com/node-fetch/-/node-fetch-2.2.0.tgz#4ee79bde909262f9775f731e3656d0db55ced5b5"
-  integrity sha512-OayFWziIxiHY8bCUyLX6sTpDH8Jsbp4FfYd1j1f7vZyfgkcOnAyM4oQR16f8a0s7Gl/viMGRey8eScYk4V4EZA==
+node-fetch@^2.3.0:
+  version "2.3.0"
+  resolved "https://registry.yarnpkg.com/node-fetch/-/node-fetch-2.3.0.tgz#1a1d940bbfb916a1d3e0219f037e89e71f8c5fa5"
+  integrity sha512-MOd8pV3fxENbryESLgVIeaGKrdl+uaYhCSSVkjeOb/31/njTpcis5aWfdqgNlHIrKOLRbMnfPINPOML2CIFeXA==
 
 node-gyp@^3.8.0:
   version "3.8.0"
@@ -9623,13 +9611,6 @@ rimraf@~2.2.6:
   resolved "https://registry.yarnpkg.com/rimraf/-/rimraf-2.2.8.tgz#e439be2aaee327321952730f99a8929e4fc50582"
   integrity sha1-5Dm+Kq7jJzIZUnMPmaiSnk/FBYI=
 
-rollup-plugin-babel@^3.0.7:
-  version "3.0.7"
-  resolved "https://registry.yarnpkg.com/rollup-plugin-babel/-/rollup-plugin-babel-3.0.7.tgz#5b13611f1ab8922497e9d15197ae5d8a23fe3b1e"
-  integrity sha512-bVe2y0z/V5Ax1qU8NX/0idmzIwJPdUGu8Xx3vXH73h0yGjxfv2gkFI82MBVg49SlsFlLTBadBHb67zy4TWM3hA==
-  dependencies:
-    rollup-pluginutils "^1.5.0"
-
 rollup-plugin-commonjs@^8.3.0:
   version "8.4.1"
   resolved "https://registry.yarnpkg.com/rollup-plugin-commonjs/-/rollup-plugin-commonjs-8.4.1.tgz#5c9cea2b2c3de322f5fbccd147e07ed5e502d7a0"
@@ -9650,14 +9631,6 @@ rollup-plugin-node-resolve@^3.3.0:
     is-module "^1.0.0"
     resolve "^1.1.6"
 
-rollup-pluginutils@^1.5.0:
-  version "1.5.2"
-  resolved "https://registry.yarnpkg.com/rollup-pluginutils/-/rollup-pluginutils-1.5.2.tgz#1e156e778f94b7255bfa1b3d0178be8f5c552408"
-  integrity sha1-HhVud4+UtyVb+hs9AXi+j1xVJAg=
-  dependencies:
-    estree-walker "^0.2.1"
-    minimatch "^3.0.2"
-
 rollup-pluginutils@^2.0.1:
   version "2.3.3"
   resolved "https://registry.yarnpkg.com/rollup-pluginutils/-/rollup-pluginutils-2.3.3.tgz#3aad9b1eb3e7fe8262820818840bf091e5ae6794"
@@ -11094,6 +11067,11 @@ whatwg-encoding@^1.0.1, whatwg-encoding@^1.0.3:
   dependencies:
     iconv-lite "0.4.24"
 
+whatwg-fetch@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/whatwg-fetch/-/whatwg-fetch-3.0.0.tgz#fc804e458cc460009b1a2b966bc8817d2578aefb"
+  integrity sha512-9GSJUgz1D4MfyKU7KRqwOjXCXTqWdFNvEr7eUBYchQiVc744mqK/MzXPNR2WsPkmkOa4ywfg8C2n8h+13Bey1Q==
+
 whatwg-mimetype@^2.1.0:
   version "2.2.0"
   resolved "https://registry.yarnpkg.com/whatwg-mimetype/-/whatwg-mimetype-2.2.0.tgz#a3d58ef10b76009b042d03e25591ece89b88d171"