Merge pull request dastergon#19 from danrl/patch-1

Added first item to new section "Roles in SRE"

README.md

@@ -99,6 +99,7 @@ Contributions are always welcome!
 * [Understanding Site Reliability Engineering through Movies and Books](http://engineering.medallia.com/blog/posts/understanding-site-reliability-engineering-through-movies-and-books/)
 * [GOTO 2017 • Site Reliability Engineering at Google • Christof Leng](https://www.youtube.com/watch?v=Cxb7a8lTv8A)
 * The Makeup of Successful Geographically-Distributed SRE Teams - [Part1](https://engineering.linkedin.com/blog/2018/03/the-makeup-of-successful-geographically-distributed-sre-teams--p) & [Part2](https://engineering.linkedin.com/blog/2018/03/the-makeup-of-successful-geographically-distributed-sre-teams--p0)
+* [Tech Leadership in SRE](https://www.youtube.com/watch?v=6G2V1xPIM64)
 
 ## Education
 * [Panel: Educating SRE](https://www.usenix.org/conference/srecon15/program/presentation/sebenik)