fix: Use yarn over npm to avoid mixed usage

Author: bebraw

package.json

@@ -16,9 +16,9 @@
     "start": "yarn build --watch",
     "lint": "eslint src --ext .ts,.js",
     "test": "npm run test:v4 && npm run test:v5",
-    "pretest:v4": "npm add @types/webpack ts-loader@8 webpack@4 --no-save",
+    "pretest:v4": "yarn-add-no-save @types/webpack ts-loader@8 webpack@4",
     "test:v4": "jest",
-    "pretest:v5": "npm add webpack@5 --no-save",
+    "pretest:v5": "yarn-add-no-save webpack@5",
     "test:v5": "jest",
     "release": "auto shipit"
   },
@@ -70,7 +70,8 @@
     "ts-loader": "^9.1.2",
     "typescript": "3.8.3",
     "webpack": "^5.36.2",
-    "webpack-cli": "^4.7.0"
+    "webpack-cli": "^4.7.0",
+    "yarn-add-no-save": "^1.0.3"
   },
   "peerDependencies": {
     "typescript": ">= 3.x",

yarn.lock

@@ -6493,6 +6493,13 @@ yargs@^15.0.1, yargs@^15.4.1:
     y18n "^4.0.0"
     yargs-parser "^18.1.2"
 
+yarn-add-no-save@^1.0.3:
+  version "1.0.3"
+  resolved "https://registry.yarnpkg.com/yarn-add-no-save/-/yarn-add-no-save-1.0.3.tgz#03540f86802a46a86db83bc7357b248cd282315b"
+  integrity sha512-ngmmxwYOogvYPjFDXGjoj35r/DteDzfiyoq5BI+kKSCCXW/I2gJA3KAgbm/7yFmcDE9CGSaORpNbYfglGYuxtA==
+  dependencies:
+    which "^2.0.2"
+
 yocto-queue@^0.1.0:
   version "0.1.0"
   resolved "https://registry.yarnpkg.com/yocto-queue/-/yocto-queue-0.1.0.tgz#0294eb3dee05028d31ee1a5fa2c556a6aaf10a1b"