Fix for webapp.getFile()

[deriven]

Using the latest strider build 1.7.7 with this plugin, I received the following error:

/home/deriven/github/Strider-CD/strider/node_modules/mongoose/lib/utils.js:413
throw err;
^

TypeError: Cannot read property 'api_url' of undefined
at Object.get (/home/deriven/github/Strider-CD/strider/node_modules/strider-gitlab/lib/api.js:25:14)
at Object.module.exports.getFile (/home/deriven/github/Strider-CD/strider/node_modules/strider-gitlab/lib/webapp.js:51:9)
at striderJson (/home/deriven/github/Strider-CD/strider/lib/backchannel.js:42:12)
at Promise. (/home/deriven/github/Strider-CD/strider/lib/backchannel.js:75:7)
at Promise. (/home/deriven/github/Strider-CD/strider/node_modules/mpromise/lib/promise.js:177:8)
at emitOne (events.js:90:13)
at Promise.emit (events.js:182:7)
at Promise.emit (/home/deriven/github/Strider-CD/strider/node_modules/mpromise/lib/promise.js:84:38)
at Promise.fulfill (/home/deriven/github/Strider-CD/strider/node_modules/mpromise/lib/promise.js:97:20)
at Promise. (/home/deriven/github/Strider-CD/strider/node_modules/mongoose/lib/model.js:1544:35)
at Promise. (/home/deriven/github/Strider-CD/strider/node_modules/mpromise/lib/promise.js:177:8)
at emitTwo (events.js:100:13)
at Promise.emit (events.js:185:7)
at Promise.emit (/home/deriven/github/Strider-CD/strider/node_modules/mpromise/lib/promise.js:84:38)
at Promise.fulfill (/home/deriven/github/Strider-CD/strider/node_modules/mpromise/lib/promise.js:97:20)
at handleSave (/home/deriven/github/Strider-CD/strider/node_modules/mongoose/lib/model.js:133:13)
at /home/deriven/github/Strider-CD/strider/node_modules/mongoose/lib/utils.js:408:16
at /home/deriven/github/Strider-CD/strider/node_modules/mongoose/node_modules/mongodb/lib/mongodb/collection/core.js:128:9
at /home/deriven/github/Strider-CD/strider/node_modules/mongoose/node_modules/mongodb/lib/mongodb/db.js:1197:7
at /home/deriven/github/Strider-CD/strider/node_modules/mongoose/node_modules/mongodb/lib/mongodb/db.js:1905:9
at Server.Base._callHandler (/home/deriven/github/Strider-CD/strider/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/base.js:453:41)
at /home/deriven/github/Strider-CD/strider/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/server.js:488:18

Added a few console.log outputs to find out that account.config didn't exist. This pull requests fixes this error by passing account. I modified the test as well.

[knownasilya]

Fix published as 1.2.3. Thanks @deriven!