RuboCopBear.py: Pin to version 0.47.1

Pin to verion 0.47.1 because tests were failing due to the
launch of a new release of rubocop 0.48.0

Fixes coala#1548

Author: yash-nisar

Gemfile

@@ -4,6 +4,6 @@ ruby '2.2.2'
 gem "csvlint"
 gem "puppet-lint", "2.1.1"
 gem "reek"
-gem "rubocop"
+gem "rubocop", "0.47.1"
 gem "scss_lint", require: false
 gem "sqlint"

bears/ruby/RuboCopBear.py

@@ -19,7 +19,7 @@ class RuboCopBear:
     """
 
     LANGUAGES = {'Ruby'}
-    REQUIREMENTS = {GemRequirement('rubocop'),
+    REQUIREMENTS = {GemRequirement('rubocop', '0.47.1'),
                     PipRequirement('pyyaml', '3.12')}
     AUTHORS = {'The coala developers'}
     AUTHORS_EMAILS = {'coala-devel@googlegroups.com'}