@babel/core was added twice into package.json about babel-upgrade

[existentialism]

@h09shais thanks for the issue! Can you post your package.json (before running the upgrade)?

[h09shais]

Sure!

{
  "version": "1.0.0",
  "name": "web",
  "private": true,
  "scripts": {},
  "devDependencies": {
    "@types/classnames": "^2.2.3",
    "@types/fbemitter": "^2.0.32",
    "@types/lodash": "^4.14.109",
    "@types/prop-types": "^15.5.3",
    "@types/react": "^16.3.14",
    "@types/react-router": "^3.0.8",
    "babel-core": "^6.26.3",
    "babel-eslint": "^7.2.1",
    "babel-plugin-transform-object-rest-spread": "^6.23.0",
    "babel-plugin-transform-runtime": "^6.23.0",
    "babel-preset-env": "^1.7.0",
    "css-loader": "^3.4.2",
    "eslint": "^4.19.1",
    "eslint-config-standard": "^11.0.0",
    "eslint-import-resolver-node": "^0.3.2",
    "eslint-plugin-import": "^2.12.0",
    "eslint-plugin-node": "^6.0.1",
    "eslint-plugin-promise": "^3.8.0",
    "eslint-plugin-react": "^7.8.2",
    "eslint-plugin-standard": "^3.1.0",
    "exports-loader": "^0.6.4",
    "extract-loader": "^0.1.0",
    "faker": "^4.1.0",
    "file-loader": "^0.11.2",
    "imports-loader": "^0.7.1",
    "mini-css-extract-plugin": "^0.9.0",
    "node-sass": "^4.13.1",
    "npm-audit-reporter-teamcity": "^0.2.3",
    "postcss-loader": "^2.1.5",
    "prop-types": "^15.6.1",
    "sass-loader": "^6.0.7",
    "style-loader": "^0.18.2",
    "svg-sprite-loader": "^3.8.0",
    "svgo": "^1.3.2",
    "svgo-loader": "^2.2.1",
    "webpack": "^4.41.5",
    "webpack-cli": "^3.3.10",
    "webpack-dev-server": "^3.10.1",
    "webpack-merge": "^4.2.2"
  },
  "dependencies": {
    "autoprefixer": "^9.7.4",
    "axios": "^0.18.1",
    "babel-loader": "^7.1.4",
    "babel-plugin-array-includes": "^2.0.3",
    "babel-plugin-transform-class-properties": "^6.24.1",
    "babel-preset-react": "^6.23.0",
    "classnames": "^2.2.5",
    "clipboard": "^2.0.4",
    "es6-promise": "^4.2.4",
    "fbemitter": "^2.1.1",
    "immutable": "^3.8.2",
    "lodash": "^4.17.15",
    "moment": "^2.22.1",
    "moment-timezone": "^0.5.17",
    "numeral": "^2.0.6",
    "object-assign": "^4.1.1",
    "react": "^16.4.0",
    "react-dom": "^16.12.0",
    "react-hot-loader": "^3.1.3",
    "react-router": "^3.2.1",
    "whatwg-fetch": "^2.0.4"
  }
}