[tests] Fix undefined fetch error for 'floating dependencies'

Pin whatwg-fetch dependence to '3.3.1'.

This fixes an error "fetch is not defined - maybe your browser targets are not covering everything you need?"
that shows up when running the tests for the floating dependencies stage.

That error comes from ember-fetch, see ember-cli/ember-fetch#547

Also remove unused ember-ajax and ember-fetch devDependencies

Author: bantic

package.json

@@ -54,7 +54,6 @@
     "babel-eslint": "^10.0.1",
     "broccoli-asset-rev": "^3.0.0",
     "ember-a11y-testing": "^0.5.0",
-    "ember-ajax": "^4.0.2",
     "ember-angle-bracket-invocation-polyfill": "^1.3.1",
     "ember-cli": "~3.1.4",
     "ember-cli-addon-docs": "0.6.13",
@@ -73,7 +72,6 @@
     "ember-disable-prototype-extensions": "^1.1.2",
     "ember-export-application-global": "^2.0.0",
     "ember-faker": "^1.5.0",
-    "ember-fetch": "^6.4.0",
     "ember-load-initializers": "^2.0.0",
     "ember-math-helpers": "^2.10.0",
     "ember-maybe-import-regenerator": "^0.1.6",
@@ -100,6 +98,7 @@
   },
   "homepage": "https://Addepar.github.io/ember-table",
   "resolutions": {
+    "ember-cli-addon-docs/ember-fetch/whatwg-fetch": "3.3.1",
     "ember-cli-page-object": "1.15.1",
     "prettier": "1.18.2"
   }

yarn.lock

@@ -5182,14 +5182,6 @@ ember-a11y-testing@^0.5.0:
     ember-cli-version-checker "^2.1.0"
     ember-get-config "^0.2.4"
 
-ember-ajax@^4.0.2:
-  version "4.0.2"
-  resolved "https://registry.npmjs.org/ember-ajax/-/ember-ajax-4.0.2.tgz#ce86d52c24289657e0a230140b06a52fe453d655"
-  integrity sha512-YeeeAQizQc5ioCeraxFo30y3W6mmUxmndF0ShI/Wvwfe8IhVw40jL42itaUHbo2CxKsNRZzQ8x3re65dGM0CrA==
-  dependencies:
-    ember-cli-babel "^6.16.0"
-    najax "^1.0.3"
-
 ember-angle-bracket-invocation-polyfill@^1.3.1:
   version "1.3.1"
   resolved "https://registry.npmjs.org/ember-angle-bracket-invocation-polyfill/-/ember-angle-bracket-invocation-polyfill-1.3.1.tgz#3dd0b91b3776a8048a943889c031fa7f9ea44ec4"
@@ -6004,7 +5996,7 @@ ember-fetch-adapter@^0.4.3:
   dependencies:
     ember-cli-babel "^6.12.0"
 
-ember-fetch@^6.2.0, ember-fetch@^6.4.0:
+ember-fetch@^6.2.0:
   version "6.7.1"
   resolved "https://registry.npmjs.org/ember-fetch/-/ember-fetch-6.7.1.tgz#778390bc9993d31cc32d429ae69a591e431e85ac"
   integrity sha512-B/s0HZWcIrDDz3wOxvAsWM2SyT4nND274aH3Othzxzax/lOJnGHKbNa+IGLrXKSja+ANeD5P8sVwDaAUw8pzpQ==
@@ -9204,11 +9196,6 @@ joi@^12.0.0:
     isemail "3.x.x"
     topo "2.x.x"
 
-jquery-deferred@^0.3.0:
-  version "0.3.1"
-  resolved "https://registry.npmjs.org/jquery-deferred/-/jquery-deferred-0.3.1.tgz#596eca1caaff54f61b110962b23cafea74c35355"
-  integrity sha1-WW7KHKr/VPYbEQlisjyv6nTDU1U=
-
 jquery@^3.2.1, jquery@^3.4.1:
   version "3.4.1"
   resolved "https://registry.npmjs.org/jquery/-/jquery-3.4.1.tgz#714f1f8d9dde4bdfa55764ba37ef214630d80ef2"
@@ -10530,15 +10517,6 @@ [email protected]:
   resolved "https://registry.npmjs.org/mute-stream/-/mute-stream-0.0.8.tgz#1630c42b2251ff81e2a283de96a5497ea92e5e0d"
   integrity sha512-nnbWWOkoWyUsTjKrhgD0dcz22mdkSnpYqbEjIm2nhwhuxlSkpywJmBo8h0ZqJdkp73mb90SssHkN4rsRaBAfAA==
 
-najax@^1.0.3:
-  version "1.0.4"
-  resolved "https://registry.npmjs.org/najax/-/najax-1.0.4.tgz#63fd8dbf15d18f24dc895b3a16fec66c136b8084"
-  integrity sha512-wsSacA+RkgY1wxRxXCT3tdqzmamEv9PLeoV/ub9SlLf2RngbPMSqc3A7H35XJDfURC0twMmZsnPdsYPkuuFSVg==
-  dependencies:
-    jquery-deferred "^0.3.0"
-    lodash.defaultsdeep "^4.6.0"
-    qs "^6.2.0"
-
 nan@^2.12.1, nan@^2.13.2:
   version "2.14.0"
   resolved "https://registry.npmjs.org/nan/-/nan-2.14.0.tgz#7818f722027b2459a86f0295d434d1fc2336c52c"
@@ -11834,7 +11812,7 @@ [email protected]:
   resolved "https://registry.npmjs.org/qs/-/qs-6.7.0.tgz#41dc1a015e3d581f1621776be31afb2876a9b1bc"
   integrity sha512-VCdBRNFTX1fyE7Nb6FYoURo/SPe62QCaAyzJvUjwRaIsc+NePBEniHlvxFmmX56+HZphIGtV0XeCirBtpDrTyQ==
 
-qs@^6.2.0, qs@^6.4.0:
+qs@^6.4.0:
   version "6.8.0"
   resolved "https://registry.npmjs.org/qs/-/qs-6.8.0.tgz#87b763f0d37ca54200334cd57bb2ef8f68a1d081"
   integrity sha512-tPSkj8y92PfZVbinY1n84i1Qdx75lZjMQYx9WZhnkofyxzw2r7Ho39G3/aEvSUdebxpnnM4LZJCtvE/Aq3+s9w==
@@ -14485,10 +14463,10 @@ whatwg-encoding@^1.0.1, whatwg-encoding@^1.0.3, whatwg-encoding@^1.0.5:
   dependencies:
     iconv-lite "0.4.24"
 
-whatwg-fetch@^3.0.0:
-  version "3.0.0"
-  resolved "https://registry.npmjs.org/whatwg-fetch/-/whatwg-fetch-3.0.0.tgz#fc804e458cc460009b1a2b966bc8817d2578aefb"
-  integrity sha512-9GSJUgz1D4MfyKU7KRqwOjXCXTqWdFNvEr7eUBYchQiVc744mqK/MzXPNR2WsPkmkOa4ywfg8C2n8h+13Bey1Q==
+whatwg-fetch@3.3.1, whatwg-fetch@^3.0.0:
+  version "3.3.1"
+  resolved "https://registry.npmjs.org/whatwg-fetch/-/whatwg-fetch-3.3.1.tgz#6c1acf37dec176b0fd6bc9a74b616bec2f612935"
+  integrity sha512-faXTmGDcLuEPBpJwb5LQfyxvubKiE+RlbmmweFGKjvIPFj4uHTTfdtTIkdTRhC6OSH9S9eyYbx8kZ0UEaQqYTA==
 
 whatwg-mimetype@^2.1.0, whatwg-mimetype@^2.2.0:
   version "2.3.0"