Release 0.11.0

Breaking Changes:

• Yew version is bumped to v0.20.
• Remove YieldStyle. This API can be easily reproduced in user code, if need be,
  but often leads to clumsy code in struct components. Use alternative API and prefer
  function_component + use_style!/styled_component.
• StyleSource does not take a lifetime argument
• Feature parser: StyleSource now eagerly parses its input.
• Feature parser: The conversion from str have been changed to TryFrom
  instead of From. If you're using yew, the IntoPropValue<StyleSource>
  impls still exist, but now panic early during conversion.
• Feature parser: This feature is now disabled by default. Use the css!, other
  macros and interpolation syntax to write styles, if you don't need to parse css at
  runtime.

Other Changes:

• The Style::new_* API is more open for accepted types of the Css parameter.
• The name of styled components now defaults to the name of the function, like in
  function_component.