Add Code of Conduct

(closes openstreetmap#3051)

Author: bhousel

CODE_OF_CONDUCT.md

@@ -0,0 +1,44 @@
+# Contributor Code of Conduct
+
+#### Guidelines
+
+* Please be respectful to one another.
+* Many contributors are volunteering their time.  We might not get to your
+issue right away.  Be patient.
+* Other contributors have different backgrounds and perspectives than you do.
+Diversity is a community strength.
+* We will disagree sometimes.  That's ok.  When this happens, assume that the
+person with whom you disagree is a smart person with good reasons for believing
+something different.
+* Everyone has bad days.  If you find yourself about to be mean to someone,
+take a break and cool off.  This project will still be here later.
+* When you make a mistake, apologize.
+
+
+#### We will not tolerate
+
+* Sexualized language or imagery
+* Hate speech
+* Personal attacks
+* Trolling or insulting/derogatory comments
+* Public or private harassment
+* Publishing other's private information
+* Plagiarism
+* Other unethical or unprofessional conduct
+
+#### Enforcement
+
+Project maintainers commit themselves to fairly enforcing this Code of Conduct.
+This means we may:
+
+* Edit or delete harmful comments, code, issues, or other contributions
+* Ban harmful users from the project, temporarily or permanently
+
+This Code of Conduct applies both within project spaces and in public spaces when an
+individual is representing the project or its community.
+
+Instances of unacceptable behavior may be reported privately to the project maintainers.
+
+#### See Also
+
+This Code of Conduct is adapted from the [Contributor Covenant](http://contributor-covenant.org).