Creating search from string doesn't work

Trying to use the function http://github-tools.github.io/github/docs/3.2.3/GitHub.html#search (using 3.4.0 but the docs aren't up for that) like this:
```js
console.log(gh.search('query'))
```
gives this error:
```
/home/heath/SyncedProjects/CredentialReminderBot/node_modules/github-api/dist/components/Requestable.js:162
requestOptions.type = requestOptions.type || 'all';
^

TypeError: Cannot create property 'type' on string 'query'
at Search._getOptionsWithDefaults (/home/heath/SyncedProjects/CredentialReminderBot/node_modules/github-api/dist/components/Requestable.js:162:33)
at new Search (/home/heath/SyncedProjects/CredentialReminderBot/node_modules/github-api/dist/components/Search.js:46:30)
at GitHub.search (/home/heath/SyncedProjects/CredentialReminderBot/node_modules/github-api/dist/components/GitHub.js:159:14)
at Object. (/home/heath/SyncedProjects/CredentialReminderBot/index.js:11:16)
at Module._compile (internal/modules/cjs/loader.js:1201:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1221:10)
at Module.load (internal/modules/cjs/loader.js:1050:32)
at Function.Module._load (internal/modules/cjs/loader.js:938:14)
at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
at internal/main/run_main_module.js:17:47
```

重現字串呼叫，並從 _getOptionsWithDefaults 開始，沿著 dist/components/GitHub.js、Search.js 和 Requestable.js 追蹤呼叫堆疊。比較文件中的搜尋呼叫與目前的引數處理方式，然後使用相關的現有搜尋檢查或專門的回歸測試驗證修正後的行為。

由索引模型根據 Issue 內容生成。