chore(core/package): remove DOWNLOAD_DIR variable from script

Author: hasezoey

packages/mongodb-memory-server-core/package.json

@@ -66,8 +66,8 @@
     "clean": "rimraf tmp lib build coverage node_modules/.cache",
     "build": "rimraf ./lib && tsc -p ./tsconfig.build.json",
     "build:tests": "rimraf ./build && tsc -p ./tsconfig.json",
-    "watch": "cross-env MONGOMS_DOWNLOAD_DIR=./tmp jest --watchAll",
-    "coverage": "cross-env MONGOMS_DOWNLOAD_DIR=./tmp jest --coverage",
+    "watch": "jest --watchAll",
+    "coverage": "jest --coverage",
     "lint": "yarn run eslint && yarn run tscheck",
     "eslint": "eslint -c ../../.eslintrc.js 'src/**/*.{js,ts}'",
     "test": "yarn run lint && yarn run coverage",