chore(*): switch from optimist to yargs and update mocha

Optimist and mocha depended upon a version of
minimist that had a security vulnerability.

package.json

@@ -33,18 +33,19 @@
     "di": "0.0.1",
     "fast-deep-equal": "^3.1.3",
     "objectdiff": "^1.1.0",
-    "optimist": "~0.6.1",
     "validate.js": "^0.12.0",
-    "winston": "^2.1.1"
+    "winston": "^2.1.1",
+    "yargs": "^16.2.0"
   },
   "devDependencies": {
     "@types/chai": "^4.1.3",
     "@types/mocha": "^5.2.1",
     "@types/node": "^10.3.1",
+    "@types/yargs": "^16.0.0",
     "chai": "^4.1.2",
     "chai-spies": "^1.0.0",
     "dgeni-packages": "^0.28.4",
-    "mocha": "^5.2.0",
+    "mocha": "^8.3.0",
     "ts-node": "^6.1.0",
     "tslint": "^5.10.0",
     "typescript": "^3.2.2"

src/gen-docs.ts

@@ -1,15 +1,21 @@
 #!/usr/bin/env node
 import {Dgeni} from './Dgeni';
+import * as yargs from 'yargs';
 
 const path = require('canonical-path');
-const myArgs = require('optimist')
+const myArgs = yargs.option('l', {
+    alias: 'log',
+    describe: 'Output log messages for this level and above',
+    type: 'string',
+    choices: ['error', 'warn', 'info', 'http','verbose', 'debug', 'silly']
+  })
   .usage('Usage: $0 path/to/mainPackage [path/to/other/packages ...] [--log level]')
-  .demand(1)
+  .demandCommand(1)
   .argv;
 
 
 // Extract the paths to the packages from the command line arguments
-const packagePaths = myArgs._;
+const packagePaths = myArgs._ as string[];
 
 // Require each of these packages and then create a new dgeni using them
 const packages = packagePaths.map((packagePath) => {