Upgrade to opentracing 1.0.0

[jcchavezs]

opentracing 1.0.0 has been released, you might want to upgrade

https://github.com/opentracing/opentracing-php/releases/tag/1.0.0

[nauxliu]

Have upgraded in the branch dev_v3, there still some works that need to be done before releasing the 3.0.

[cawolf]

Hey @nauxliu , do you need some help upgrading? We are depending on the upgrade and would like to contribute. :)

[jukylin]

@cawolf We are so glad you can help. We'd like to ask you to help improve the document. 😄

[dmnbars]

@jukylin any news about 3.0 date of release?

[cawolf]

Just FYI: in order to maintain our opentracing bundles for symfony, we opted into publishing our fork of this library as auxmoney/jaeger-php and released v3.