Add some silly tests for report generation
user
```ruby
class TestReportGeneration < Test::Unit::TestCase
  Report = Brakeman.run("#{TEST_PATH}/apps/rails3.2").report

  def test_html_sanity
    report = Report.to_html

    assert report.is_a? String
    assert report.match(/\A<!DOCTYPE HTML SYSTEM>.*<\/html>\z/m)
  end

  def test_json_sanity
    report = Report.to_json
    expected_keys = ["scan_info", "warnings", "errors"]

    assert report.is_a? String

    report_hash = MultiJson.load report

    assert (expected_keys - report_hash.keys).empty?, "Expected #{expected_keys - report_hash.keys} to be empty"
  end

  def test_csv_sanity
    report = Report.to_csv

    assert report.is_a? String
  end

  def test_tabs_sanity
    report = Report.to_tabs

    assert report.is_a? String
  end

  def test_text_sanity
    report = Report.to_s

    assert report.is_a? String
  end
end
```
assistant