Upgrade yapf to 0.28

Upgrades yapf to newest version, 0.28.0, and runs the formatter to
update all existing code.

Change-Id: I7b2cb0dfd80dbe7bad37f6046c7465f7abe71d1e

spyglass_plugin_xls/excel_parser.py

@@ -28,7 +28,6 @@ LOG = logging.getLogger(__name__)
 
 class ExcelParser(object):
     """Parse data from excel into a dict"""
-
     def __init__(
             self, file_name: str, excel_specs: str, spec: str = 'xl_spec'):
         """Initializes an ExcelParser to extract data from the Excel workbook

test-requirements.txt

@@ -6,7 +6,7 @@ pytest-cov==2.6.1
 # Formatting
 flake8==3.7.8
 flake8-import-order==0.18.1
-yapf==0.27.0
+yapf==0.28.0
 
 # Linting
 hacking==1.1.0

tests/unit/test_excel.py

@@ -40,7 +40,6 @@ SITE_CONFIG_PATH = os.path.join(FIXTURE_DIR, 'site_config.yaml')
 @pytest.mark.usefixtures('site_data')
 class TestExcelPlugin(unittest.TestCase):
     """Tests for ExcelPlugin"""
-
     def test___init__(self):
         region = 'test_region'
         result = ExcelPlugin(