message: Don't rely on Jinja2's lstrip_blocks
  Travis has Jinja 2.6 but the option appeared in Jinj 2.7. Manually
  perform the stripping in the preprocessing step instead.
diff: @@ -213,7 +213,14 @@ class PreprocessingLoader(jinja2.BaseLoader):
  numends = (len(self.blockend.split(line)) - 1) // 2
  indentation_level -= numends
  - result.append(self.remove_indentation(line, indentation_level))
  + line = self.remove_indentation(line, indentation_level)
  +
  + # Manually perform the lstrip_blocks jinja2 env options as it available starting from 2.7
  + # and Travis only has Jinja 2.6
  + if line.lstrip().startswith('{%'):
  + line = line.lstrip()
  +
  + result.append(line)
  numstarts = (len(self.blockstart.split(line)) - 1) // 2
  indentation_level += numstarts
  @@ -233,7 +240,7 @@ class PreprocessingLoader(jinja2.BaseLoader):
  FileRender = namedtuple('FileRender', ['template', 'output', 'params_dicts'])
  def do_renders(renders, template_dir, output_dir):
  - env = jinja2.Environment(loader=PreprocessingLoader(template_dir), trim_blocks=True, lstrip_blocks=True, line_comment_prefix='//*')
  + env = jinja2.Environment(loader=PreprocessingLoader(template_dir), trim_blocks=True, line_comment_prefix='//*')
  for render in renders:
  params = {}
  for param_dict in render.params_dicts:
  