[Breaking] drop support for all but eslint 6/7, and jest 25/26

Author: ljharb

.travis.yml

@@ -7,88 +7,15 @@ node_js:
   - 10
 install:
   - 'yarn add "eslint@${ESLINT}" "jest@${JEST}" "babel-jest@${JEST}" --ignore-engines'
-  - 'if [ "${ESLINT-}" = 4 ]; then yarn add eslint-config-airbnb-base@13 --ignore-engines; fi'
   - 'yarn --ignore-engines'
 env:
-  - 'ESLINT=4 JEST=21'
-  - 'ESLINT=5 JEST=21'
-  - 'ESLINT=6 JEST=21'
-  - 'ESLINT=7 JEST=21'
-  - 'ESLINT=4 JEST=22'
-  - 'ESLINT=5 JEST=22'
-  - 'ESLINT=6 JEST=22'
-  - 'ESLINT=7 JEST=22'
-  - 'ESLINT=4 JEST=23'
-  - 'ESLINT=5 JEST=23'
-  - 'ESLINT=6 JEST=23'
-  - 'ESLINT=7 JEST=23'
-  - 'ESLINT=4 JEST=24'
-  - 'ESLINT=5 JEST=24'
-  - 'ESLINT=6 JEST=24'
-  - 'ESLINT=7 JEST=24'
-  - 'ESLINT=4 JEST=25'
-  - 'ESLINT=5 JEST=25'
   - 'ESLINT=6 JEST=25'
   - 'ESLINT=7 JEST=25'
-  - 'ESLINT=4 JEST=26'
-  - 'ESLINT=5 JEST=26'
   - 'ESLINT=6 JEST=26'
   - 'ESLINT=7 JEST=26'
 matrix:
-  # jest 21: 4+
-  # jest 22: 6+
   # jest 25: 8+
   include:
-    # eslint 4, node 4/6/8
-    - node_js: '4'
-      env: 'ESLINT=4 JEST=21'
-    - node_js: '6'
-      env: 'ESLINT=4 JEST=21'
-    - node_js: '8'
-      env: 'ESLINT=4 JEST=21'
-    - node_js: '6'
-      env: 'ESLINT=4 JEST=22'
-    - node_js: '8'
-      env: 'ESLINT=4 JEST=22'
-    - node_js: '6'
-      env: 'ESLINT=4 JEST=23'
-    - node_js: '8'
-      env: 'ESLINT=4 JEST=23'
-    - node_js: '6'
-      env: 'ESLINT=4 JEST=24'
-    - node_js: '8'
-      env: 'ESLINT=4 JEST=24'
-    - node_js: '8'
-      env: 'ESLINT=4 JEST=25'
-
-    # eslint 5, node 6/8
-    - node_js: '6'
-      env: 'ESLINT=5 JEST=21'
-    - node_js: '8'
-      env: 'ESLINT=5 JEST=21'
-    - node_js: '6'
-      env: 'ESLINT=5 JEST=22'
-    - node_js: '8'
-      env: 'ESLINT=5 JEST=22'
-    - node_js: '6'
-      env: 'ESLINT=5 JEST=23'
-    - node_js: '8'
-      env: 'ESLINT=5 JEST=23'
-    - node_js: '6'
-      env: 'ESLINT=5 JEST=24'
-    - node_js: '8'
-      env: 'ESLINT=5 JEST=24'
-    - node_js: '8'
-      env: 'ESLINT=5 JEST=25'
-
     # eslint 6, node 8
-    - node_js: '8'
-      env: 'ESLINT=6 JEST=21'
-    - node_js: '8'
-      env: 'ESLINT=6 JEST=22'
-    - node_js: '8'
-      env: 'ESLINT=6 JEST=23'
-    - node_js: '8'
-      env: 'ESLINT=6 JEST=24'
     - node_js: '8'
       env: 'ESLINT=6 JEST=25'

package.json

@@ -27,7 +27,7 @@
     "chalk": "^2.4.1",
     "cosmiconfig": "^5.0.0",
     "create-jest-runner": "^0.5.3",
-    "eslint": "^4.0.0 || ^5.0.0 || ^6.0.0 || ^7.0.0"
+    "eslint": "^6 || ^7"
   },
   "devDependencies": {
     "@babel/cli": "^7.1.0",
@@ -40,15 +40,15 @@
     "eslint-plugin-jest": "^23.13.2",
     "eslint-plugin-prettier": "^3.1.3",
     "execa": "^1.0.0",
-    "jest": "^21.0.0 || ^22.0.0 || ^23.0.0 || ^24.0.0 || ^25.1.0 || ^26.0.0",
+    "jest": "^25.1 || ^26",
     "jest-watch-select-projects": "^0.1.1",
     "jest-watch-typeahead": "^0.3.1",
     "prettier": "^1.14.3",
     "rimraf": "^2.6.2"
   },
   "peerDependencies": {
-    "eslint": "^4.0.0 || ^5.0.0 || ^6.0.0 || ^7.0.0",
-    "jest": "^21.0.0 || ^22.0.0 || ^23.0.0 || ^24.0.0 || ^25.1.0 || ^26.0.0"
+    "eslint": "^6 || ^7",
+    "jest": "^25.1 || ^26"
   },
   "prettier": {
     "proseWrap": "never",