* Remove AddLink & Link from Span Interface
I have remove AddLink and Link from the interface and all it refereneces and replaced AddLink with addlink, Also Removed respective unit tests
Signed-off-by: vineeth <vineethpothulapati@outlook.com>
* removing the unused code from unit tests
Signed-off-by: VineethReddy02 <vineethpothulapati@outlook.com>
* Provide conformance tests for tracers
The test harness may be used to ensure that a given tracer behaves
according to the expectations set by the API.
* Add `ToMatchError` matcher
* Use DeepEqual to compare unknown types in matchers
Unlike basic `==`/`!=`, `reflect.DeepEqual` can compare arbitrary
types (e.g., `[]string` to `[]string`)
* Use struct instead of string for test context key
