ARROW-5603: [Python] Register custom pytest markers to avoid warnings
ARROW-5603: [Python] Register custom pytest markers to avoid warnings

https://issues.apache.org/jira/browse/ARROW-5603

Author: Joris Van den Bossche <jorisvandenbossche@gmail.com>

Closes #4570 from jorisvandenbossche/ARROW-5603-pytest-markers and squashes the following commits:

72feab5b1 <Joris Van den Bossche> ARROW-5603:  register custom pytest markers to avoid warnings

majetideepak/arrow,icexelloss/arrow,wesm/arrow,xhochy/arrow,renesugar/arrow,kou/arrow,xhochy/arrow,wesm/arrow,cpcloud/arrow,wesm/arrow,cpcloud/arrow,laurentgo/arrow,wesm/arrow,laurentgo/arrow,laurentgo/arrow,icexelloss/arrow,apache/arrow,xhochy/arrow,cpcloud/arrow,icexelloss/arrow,renesugar/arrow,icexelloss/arrow,renesugar/arrow,majetideepak/arrow,apache/arrow,laurentgo/arrow,apache/arrow,cpcloud/arrow,laurentgo/arrow,wesm/arrow,xhochy/arrow,cpcloud/arrow,apache/arrow,kou/arrow,apache/arrow,xhochy/arrow,icexelloss/arrow,laurentgo/arrow,renesugar/arrow,cpcloud/arrow,kou/arrow,renesugar/arrow,renesugar/arrow,laurentgo/arrow,cpcloud/arrow,apache/arrow,laurentgo/arrow,xhochy/arrow,apache/arrow,icexelloss/arrow,icexelloss/arrow,renesugar/arrow,majetideepak/arrow,icexelloss/arrow,renesugar/arrow,renesugar/arrow,wesm/arrow,xhochy/arrow,wesm/arrow,kou/arrow,wesm/arrow,laurentgo/arrow,majetideepak/arrow,renesugar/arrow,apache/arrow,cpcloud/arrow,wesm/arrow,xhochy/arrow,xhochy/arrow,laurentgo/arrow,majetideepak/arrow,majetideepak/arrow,kou/arrow,icexelloss/arrow,wesm/arrow,wesm/arrow,laurentgo/arrow,wesm/arrow,icexelloss/arrow,renesugar/arrow,renesugar/arrow,kou/arrow,renesugar/arrow,icexelloss/arrow,icexelloss/arrow,renesugar/arrow,majetideepak/arrow,wesm/arrow,xhochy/arrow,xhochy/arrow,apache/arrow,icexelloss/arrow,laurentgo/arrow,majetideepak/arrow,apache/arrow,cpcloud/arrow,apache/arrow,laurentgo/arrow,xhochy/arrow,cpcloud/arrow,laurentgo/arrow,majetideepak/arrow,majetideepak/arrow,majetideepak/arrow,icexelloss/arrow,kou/arrow,kou/arrow,laurentgo/arrow,xhochy/arrow,cpcloud/arrow,xhochy/arrow,cpcloud/arrow,majetideepak/arrow,apache/arrow,kou/arrow,kou/arrow,cpcloud/arrow,apache/arrow,renesugar/arrow,majetideepak/arrow,cpcloud/arrow,kou/arrow,kou/arrow,majetideepak/arrow,majetideepak/arrow,apache/arrow,kou/arrow,wesm/arrow,xhochy/arrow,kou/arrow