ARROW-3015: [Python] Fix typo in uint8() docstring
ARROW-3015: [Python] Fix typo in uint8() docstring

Author: Antoine Pitrou <antoine@python.org>

Closes #2414 from pitrou/ARROW-3015-uint8-doc-typo and squashes the following commits:

8a418ade <Antoine Pitrou> ARROW-3015:  Fix typo in uint8() docstring

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