Updating go depencancies. Switching to go1.6 vendoring (#2949)

vendor/github.com/go-sql-driver/mysql/CONTRIBUTING.md

@@ -0,0 +1,23 @@
+# Contributing Guidelines
+
+## Reporting Issues
+
+Before creating a new Issue, please check first if a similar Issue [already exists](https://github.com/go-sql-driver/mysql/issues?state=open) or was [recently closed](https://github.com/go-sql-driver/mysql/issues?direction=desc&page=1&sort=updated&state=closed).
+
+## Contributing Code
+
+By contributing to this project, you share your code under the Mozilla Public License 2, as specified in the LICENSE file.
+Don't forget to add yourself to the AUTHORS file.
+
+### Code Review
+
+Everyone is invited to review and comment on pull requests.
+If it looks fine to you, comment with "LGTM" (Looks good to me).
+
+If changes are required, notice the reviewers with "PTAL" (Please take another look) after committing the fixes.
+
+Before merging the Pull Request, at least one [team member](https://github.com/go-sql-driver?tab=members) must have commented with "LGTM".
+
+## Development Ideas
+
+If you are looking for ideas for code contributions, please check our [Development Ideas](https://github.com/go-sql-driver/mysql/wiki/Development-Ideas) Wiki page.