remove openzeppelin

contracts/package-lock.json

@@ -3789,11 +3789,6 @@
         "mimic-fn": "^1.0.0"
       }
     },
-    "openzeppelin-solidity": {
-      "version": "2.3.0",
-      "resolved": "https://registry.npmjs.org/openzeppelin-solidity/-/openzeppelin-solidity-2.3.0.tgz",
-      "integrity": "sha512-QYeiPLvB1oSbDt6lDQvvpx7k8ODczvE474hb2kLXZBPKMsxKT1WxTCHBYrCU7kS7hfAku4DcJ0jqOyL+jvjwQw=="
-    },
     "optionator": {
       "version": "0.8.2",
       "resolved": "https://registry.npmjs.org/optionator/-/optionator-0.8.2.tgz",

contracts/package.json

@@ -18,7 +18,6 @@
     "chai-as-promised": "^7.1.1",
     "circomlib": "git+https://github.com/kobigurk/circomlib.git#323966c0584bafebf9652681c44d9ea348fe9bb5",
     "ganache-cli": "^6.4.5",
-    "openzeppelin-solidity": "^2.3.0",
     "truffle": "^5.0.20",
     "truffle-artifactor": "^4.0.22",
     "web3-utils": "^1.0.0-beta.55"