clean up scripts section

package.json

@@ -26,8 +26,6 @@
     "homepage": "https://github.com/eventbrite/eventbrite-sdk-javascript#readme",
     "license": "MIT",
     "scripts": {
-        "check:size": "bundlesize",
-        "precheck:size": "yarn gulp build:dist:min",
         "check:static": "npm-run-all --parallel lint tsc",
         "format": "prettier-eslint --write",
         "lint": "jest --config=jest-lint.config.js",
@@ -36,12 +34,10 @@
         "build": "npm-run-all build:targets gen:declarations",
         "build:targets": "gulp build",
         "prebuild:targets": "rm -rf dist && rm -rf lib",
-        "tsc": "tsc",
+        "postbuild": "bundlesize",
+        "start": "jest --watch",
         "test": "jest --config=jest-test.config.js",
-        "test:ci": "yarn test --ci",
-        "test:watch": "yarn test --watch",
-        "validate": "npm-run-all --parallel check:static check:size test:ci",
-        "validate:watch": "jest --watch"
+        "validate": "jest"
     },
     "lint-staged": {
         "*.{ts,js}": [