Add JWT setters

.eslintrc

@@ -0,0 +1,84 @@
+{
+  "rules": {
+    "curly": [
+      2
+    ],
+    "eqeqeq": [
+      2
+    ],
+    "indent": [
+      2,
+      2,
+      {
+        "SwitchCase": 1
+      }
+    ],
+    "linebreak-style": [
+      2,
+      "unix"
+    ],
+    "new-cap": [
+      2,
+      {
+        "properties": false
+      }
+    ],
+    "no-unused-vars": [
+      2,
+      {
+        "vars": "all",
+        "args": "after-used"
+      }
+    ],
+    "no-use-before-define": [
+      2
+    ],
+    "no-trailing-spaces": [
+      2
+    ],
+    "quotes": [
+      2,
+      "single"
+    ],
+    "semi": [
+      2,
+      "always"
+    ],
+    "wrap-iife": [
+      2,
+      "outside"
+    ],
+    "strict": [
+      2,
+      "global"
+    ],
+    "brace-style": 2,
+    "block-spacing": [
+      2,
+      "always"
+    ],
+    "keyword-spacing": [2, {"before": true, "after": true, "overrides": {}}],
+    "space-before-blocks": 2,
+    "space-before-function-paren": [2, {"anonymous": "always", "named": "never"}],
+    "comma-spacing": [2, {"before": false, "after": true}],
+    "comma-style": [2, "last"],
+    "no-lonely-if": 2,
+    "array-bracket-spacing": [2, "never"],
+    "no-spaced-func": [2],
+    "space-in-parens": [2, "never"],
+    "space-infix-ops": 2
+  },
+  "globals": {
+    "after": true,
+    "afterEach": true,
+    "before": true,
+    "beforeEach": true,
+    "describe": true,
+    "it": true
+  },
+  "env": {
+    "es6": true,
+    "node": true
+  },
+  "extends": "eslint:recommended"
+}

.jshintignore

@@ -0,0 +1,4 @@
+test/rsa.pub
+test/rsa.priv
+test/ecdsa.pub
+test/ecdsa.priv

README.md

@@ -219,6 +219,31 @@ jwt.setNotbefore(); // Remove the exp claim
 ```
 
 
+## Error Handling
+
+If an error occurs then one of the following error types will either be thrown
+or passed as the first argument in a callback.
+
+Type                                    | Description
+----------------------------------------|--------------------------------------
+JwtError                                | Base type. All errors implement this.
+JwtParseError                           | Jwt cannot be parsed.
+UnsupportedSigningAlgorithmJwtError     | Unsupported signing algorithm.
+SigningKeyRequiredJwtError              | Signing key is required.
+NotActiveJwtParseError                  | Jwt not active.
+ExpiredJwtParseError                    | Jwt is expired.
+SignatureAlgorithmMismatchJwtParseError | Unexpected signature algorithm.
+SignatureMismatchJwtParseError          | Signature verification failed.
+
+To handle a specific error, simply compare the instance of the error received to one of
+the error types above, as shown in the example below:
+
+```javascript
+if (err instanceof nJwt.JwtParseError) {
+  console.log('Unable to parse the provided jwt.');
+}
+```
+
 ## Supported Algorithms
 
 "alg" Value | Algorithm used