message: build(package): remove copy test script
diff: "scripts": {
  "precommit": "lint-staged",
  "commitmsg": "validate-commit-msg",
  - "build_all": "npm-run-all compat_build_all clean_dist copy_sources build_cjs build_esm5 build_esm2015 build_esm5_for_rollup build_umd build_types build_legacy_reexport build_migrations generate_packages copy_for_tests",
  + "build_all": "npm-run-all compat_build_all clean_dist copy_sources build_cjs build_esm5 build_esm2015 build_esm5_for_rollup build_umd build_types build_legacy_reexport build_migrations generate_packages",
  "build_cjs": "npm-run-all clean_dist_cjs compile_dist_cjs",
  "build_esm5": "npm-run-all clean_dist_esm5 compile_dist_esm5",
  "build_esm5_for_rollup": "npm-run-all clean_dist_esm5_for_rollup compile_dist_esm5_for_rollup && mkdirp dist/esm5_for_rollup/node_modules && shx cp -r ./dist-compat/package ./dist/esm5_for_rollup/node_modules/rxjs-compat",
  "build_umd": "npm-run-all clean_dist_global && mkdirp ./dist/global && node ./tools/make-umd-bundle.js && npm-run-all build_closure_core",
  "build_perf": "webdriver-manager update && npm-run-all build_cjs build_global perf",
  "build_docs": "npm-run-all build_global build_esm2015_for_docs build_cjs tests2png decision_tree_widget && esdoc -c esdoc.json && npm-run-all clean_dist_esm2015",
  - "build_spec": "npm-run-all build_cjs generate_packages copy_for_tests",
  + "build_spec": "npm-run-all build_cjs generate_packages",
  "build_spec_full": "npm-run-all compat_build_cjs compile_legacy_reexport compat_generate_packages build_spec",
  "build:spec:browser": "echo \"Browser test is not working currently\" && exit -1 && webpack --config spec/support/webpack.mocha.config.js",
  "clean_dist": "shx rm -rf ./dist",
  "compile_dist_types": "tsc -p ./tsconfig/tsconfig.types.json",
  "compile_legacy_reexport": "tsc -p ./tsconfig/tsconfig.legacy-reexport.json",
  "copy_sources": "mkdirp dist && shx cp -r ./src/ ./dist/src",
  - "copy_for_tests": "shx rm -rf ./spec-build && shx cp -r ./spec/ ./spec-build/ && mkdirp ./spec-build/node_modules && shx cp -r ./dist/package/ ./spec-build/node_modules/rxjs && shx cp -r ./dist-compat/package/ ./spec-build/node_modules/rxjs-compat",
  "decision_tree_widget": "cd doc/decision-tree-widget && npm run build && cd ../..",
  "doctoc": "doctoc CONTRIBUTING.md",
  "generate_packages": "node .make-packages.js",
  