chore(travis): create logs folder before script run

Now, how to solve this locally?..

.travis.yml

@@ -4,14 +4,15 @@ node_js:
 before_install:
   - 'npm install -g bower grunt-cli'
 before_script:
+  - mkdir -p '/logs'
   - 'export DISPLAY=:99.0'
   - 'sh -e /etc/init.d/xvfb start'
 script:
   - 'npm test'
   - 'npm run coveralls'
   - 'npm run saucelabs'
 after_script:
-  - 'cat logs/karma.log'
+  - 'cat /logs/karma.log'
 env:
   global:
     - secure: L+EPka9O38GaLwg3xqr6p9rwvwy4MnQH0Fba8Qlt1M5QzLRz3e9JdVvxCQrQlETR5Guc5CN1dLOQFhVyYoCFNcOs3VkeD/mnegq16LwFE9vcmxySRqleUja3eCQ4HQJP99pSiCHYQVGvoZUf82nYNz6bh7JusbGapyyUF4Nl1TU=

karma.conf.js

@@ -133,7 +133,7 @@ module.exports = function(config) {
 		// Debug logging into a file, that we print out at the end of the build.
 		config.loggers.push({
 			type: 'file',
-			filename: 'logs/karma.log'
+			filename: '/logs/karma.log'
 		});
 	}
 };