tracing 0.1.34

This release includes bug fixes for the "log" support feature and for the use of
both scoped and global default dispatchers in the same program.

Fixed

• Failure to use the global default dispatcher when a thread sets a local
  default dispatcher before the global default is set (#2065)
• log: Compilation errors due to async block/fn futures becoming !Send
  when the "log" feature flag is enabled (#2073)
• Broken links in documentation (#2068)

Thanks to @ben0x539 for contributing to this release!