fix: use dedicated .pylintrc for opentracing example and add newline

Author: chimchim89

docs/examples/opentracing/.pylintrc

@@ -0,0 +1,9 @@
+[MASTER]
+init-hook='import sys; sys.path.insert(0, ".")'
+
+[MESSAGES CONTROL]
+disable=missing-docstring,
+        too-few-public-methods
+
+[FORMAT]
+expected-line-ending-format=

tox.ini

@@ -417,4 +417,5 @@ deps =
 setenv =
   PYTHONPATH = {toxinidir}/docs/examples/opentracing
 commands =
-  pylint --rcfile {toxinidir}/.pylintrc --disable=unexpected-line-ending-format {toxinidir}/docs/examples/opentracing
+  pylint --rcfile {toxinidir}/docs/examples/opentracing/.pylintrc {toxinidir}/docs/examples/opentracing
+