SettingsTest.py: Tests to increase branch coverage

Modifying tests in SettingsTest.py file to increase branch coverage
of ``if ext in exts:`` in get_extensions function to 100%.

Closes #279

.nocover.yaml

@@ -32,9 +32,6 @@ nocover_regexes:
   - def autofill_value
   - def is_autofill_possible
   - def require_setting
-  # generation/Settings.py::get_extensions
-  # https://github.com/coala/coala-quickstart/issues/279
-  - if ext in exts
   # generation/SettingsClass.py::fillup_optional_settings
   # https://github.com/coala/coala-quickstart/issues/280
   - if inside_annot

setup.cfg

@@ -84,7 +84,6 @@ exclude_lines =
   def autofill_value
   def is_autofill_possible
   def require_setting
-  if ext in exts
   if inside_annot
   if hasattr.*generate_config
   def is_glob_exp

tests/generation/SettingsTest.py

@@ -77,7 +77,7 @@ def test_allow_complete_section_mode_with_ignore_globs(self):
 
     def test_allow_complete_section_mode(self):
         project_dir = "/repo"
-        project_files = ['/repo/hello.html']
+        project_files = ['/repo/hello.html', '/repo/readme.txt']
         ignore_globs = []
 
         used_languages = list(get_used_languages(project_files))