fix: abbreviated cli flags

BREAKING CHANGE: --version no longer returns a version number. First of all, semantic-release goes with removing the version number from your package.json. But also, the version number really shouldn't matter.

Furthermore, you can now use all flags in an abbreviated manner as long as they are unambiguous. For example:
`android-icons --si xxhdpi` works just like `android-icons --size xxhdpi` does. This works for all flags.

bin/android-icons.js

@@ -1,28 +1,38 @@
 #!/usr/bin/env node
 'use strict'
 var abbrev = require('abbrev')
-var argv = require('minimist')(process.argv.slice(2), abbrev('help', 'version', 'size', 'format'))
-var pkg = require('../package.json')
+var argv = require('yargs')
 var icons = require('../')
 
-function help () {
-  console.log([
-    pkg.description,
-    '',
-    'Use `--format json` to set output to JSON.',
-    'Get specifc icon by size or name by using `--size`.',
-    '',
-    'Examples:',
-    '  $ android-icons --size 48',
-    '  mdpi.png,48',
-    '',
-    '  $ android-icons --size 48 --format json',
-    '  {"name":"mdpi.png","width":48}',
-    '',
-    '  $ android-icons --size xhdpi',
-    '  xhdpi.png,96'
-  ].join('\n'))
-}
+// help
+argv.help('help')
+argv.alias('h', 'help')
+
+// register abbreviated aliases
+var abbrevs = abbrev(['help', 'size', 'format'])
+var aliases = Object.keys(abbrevs)
+aliases.forEach(function (alias) {
+  if (alias !== abbrevs[alias]) {
+    argv.alias(alias, abbrevs[alias])
+  }
+})
+
+// document options
+argv.option('size', {
+  description: 'number of pixels (width) or string identifiying the icon image'
+})
+argv.option('format', {
+  description: 'format of the output to stdout (csv or json)'
+})
+
+// will show up in help
+argv.usage('Usage: android-icons [options]')
+
+argv.example('$ android-icons --size 48', 'mdpi.png,48')
+argv.example('$ android-icons --size 48 --format json', '{"name":"mdpi.png","width":48}')
+argv.example('$ android-icons --size xhdpi', 'xhdpi.png,96')
+
+argv = argv.argv
 
 function formatLog (icons, argv) {
   var format = (argv.format || 'csv').toLowerCase()
@@ -38,12 +48,8 @@ function formatLog (icons, argv) {
 }
 
 function cli () {
-  if (argv.help) return help()
-
-  if (argv.version) return console.log(pkg.version)
-
   var options = {
-    size: argv.size || argv.s
+    size: argv.size
   }
 
   var output = icons(options)

package.json

@@ -6,7 +6,7 @@
   "bin": "./bin/android-icons.js",
   "dependencies": {
     "abbrev": "^1.0.5",
-    "minimist": "^1.1.0"
+    "yargs": "^3.7.0"
   },
   "devDependencies": {
     "semantic-release": "^3.0.4",