add yarn support

Author: DavidWells

lib/parser.js

@@ -4,6 +4,8 @@ function getScriptName(command) {
   return command
     .replace(/^npm run\s/, '')
     .replace(/^npm\s/, '')
+    .replace(/^yarn run\s/, '')
+    .replace(/^yarn\s/, '')
 }
 
 function getSteps(pkg, scriptName) {

usage.js

@@ -6,34 +6,35 @@ const parse = require('./lib')
 const packagePath = path.join(__dirname, 'tests/fixtures/one.json')
 
 async function runParser() {
-  const parsed = await parse(packagePath, 'npm run build')
+  const parsed = await parse(packagePath, 'yarn run build')
   console.log(util.inspect(parsed, {
     showHidden: false,
     depth: null
   }))
-  /* Parsed contents
-  {
-    command: 'npm run build',
-    steps: [{
-        name: 'prebuild',
-        raw: 'echo a && npm run foo',
-        parsed: ['echo a', 'echo foo']
-      },
-      {
-        name: 'build',
-        raw: 'echo b && npm run cleanup',
-        parsed: ['echo b', 'echo cleanup']
-      },
-      {
-        name: 'postbuild',
-        raw: 'echo c',
-        parsed: 'echo c'
-      }
-    ],
-    raw: ['echo a', 'echo foo', 'echo b', 'echo cleanup', 'echo c'],
-    combined: 'echo a && echo foo && echo b && echo cleanup && echo c'
-  }
-  */
 }
 
 runParser()
+
+/* Parsed contents
+{
+  command: 'npm run build',
+  steps: [{
+      name: 'prebuild',
+      raw: 'echo a && npm run foo',
+      parsed: ['echo a', 'echo foo']
+    },
+    {
+      name: 'build',
+      raw: 'echo b && npm run cleanup',
+      parsed: ['echo b', 'echo cleanup']
+    },
+    {
+      name: 'postbuild',
+      raw: 'echo c',
+      parsed: 'echo c'
+    }
+  ],
+  raw: ['echo a', 'echo foo', 'echo b', 'echo cleanup', 'echo c'],
+  combined: 'echo a && echo foo && echo b && echo cleanup && echo c'
+}
+*/