Change prepack npm script to prepare (take 2) (#1755)

* update truffle to include bugfix

* change prepack script to prepare

* add npx in compile script

* fix for older node

* rename script file to prepare

(cherry picked from commit 036dd9bd6e)

package.json

@@ -20,7 +20,7 @@
     "lint:js": "eslint .",
     "lint:js:fix": "eslint . --fix",
     "lint:sol": "solhint --max-warnings 0 \"contracts/**/*.sol\"",
-    "prepack": "node scripts/prepack.js",
+    "prepare": "node scripts/prepare.js",
     "release": "scripts/release/release.sh",
     "version": "scripts/release/update-changelog-release-date.js && scripts/release/update-ethpm-version.js",
     "test": "scripts/test.sh"
@@ -62,6 +62,6 @@
     "solhint": "^1.5.0",
     "solidity-coverage": "github:rotcivegaf/solidity-coverage#5875f5b7bc74d447f3312c9c0e9fc7814b482477",
     "solidity-docgen": "^0.2.0-alpha.0",
-    "truffle": "^5.0.0"
+    "truffle": "^5.0.18"
   }
 }