remove superfluous package.json file in payments/

src/payments/package.json

@@ -1,40 +0,0 @@
-{
-  "name": "bitcoinjs-playground",
-  "version": "1.0.0",
-  "description": "Go nuts!",
-  "main": "_testnet.js",
-  "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
-  },
-  "repository": {
-    "type": "git",
-    "url": "git+https://github.com/bitcoinjs/bitcoinjs-playground.git"
-  },
-  "author": "",
-  "license": "ISC",
-  "bugs": {
-    "url": "https://github.com/bitcoinjs/bitcoinjs-playground/issues"
-  },
-  "homepage": "https://github.com/bitcoinjs/bitcoinjs-playground#readme",
-  "dependencies": {
-    "async": "^2.5.0",
-    "bech32": "^1.1.3",
-    "bip21": "^2.0.1",
-    "bip32-utils": "^0.11.1",
-    "bip38": "^2.0.2",
-    "bip39": "^2.5.0",
-    "bip69": "^2.1.1",
-    "bitcoin-ops": "^1.4.1",
-    "bitcoinjs-lib": "^3.3.2",
-    "bs58": "^4.0.1",
-    "bs58check": "^2.1.1",
-    "cb-http-client": "^0.2.3",
-    "coinselect": "^3.1.11",
-    "dhttp": "^2.4.2",
-    "merkle-lib": "^2.0.10",
-    "mocha": "^5.0.5",
-    "tape": "^4.9.0",
-    "typeforce": "^1.11.4",
-    "utxo": "^2.0.4"
-  }
-}