added Certificate model

models/certificate.js

@@ -0,0 +1,91 @@
+module.exports = (sequelize, { STRING, BOOLEAN, INTEGER, TEXT, ARRAY, DECIMAL, DOUBLE }) => {
+  const Certificate = sequelize.define(
+    'Certificate',
+    {
+      address: {
+        type   : STRING,
+        default: null,
+      },
+      amount: {
+        type   : STRING,
+        default: null,
+      },
+      claimId: {
+        type   : STRING,
+        default: null,
+      },
+      claimSequence: {
+        type   : INTEGER,
+        default: null,
+      },
+      decodedClaim: {
+        type   : BOOLEAN,
+        default: null,
+      },
+      depth: {
+        type   : INTEGER,
+        default: null,
+      },
+      effectiveAmount: {
+        type   : STRING,
+        default: null,
+      },
+      hasSignature: {
+        type   : BOOLEAN,
+        default: null,
+      },
+      height: {
+        type   : STRING,
+        default: null,
+      },
+      hex: {
+        type   : TEXT('long'),
+        default: null,
+      },
+      name: {
+        type   : STRING,
+        default: null,
+      },
+      nout: {
+        type   : INTEGER,
+        default: null,
+      },
+      txid: {
+        type   : STRING,
+        default: null,
+      },
+      validAtHeight: {
+        type   : STRING,
+        default: null,
+      },
+      outpoint: {
+        type   : STRING,
+        default: null,
+      },
+      valueVersion: {
+        type   : STRING,
+        default: null,
+      },
+      claimType: {
+        type   : STRING,
+        default: null,
+      },
+      certificateVersion: {
+        type   : STRING,
+        default: null,
+      },
+      keyType: {
+        type   : STRING,
+        default: null,
+      },
+      publicKey: {
+        type   : TEXT('long'),
+        default: null,
+      },
+    },
+    {
+      freezeTableName: true,
+    }
+  );
+  return Certificate;
+};