ARROW-2178: [JS] Fix JS html FileReader example
ARROW-2178: [JS] Fix JS html FileReader example

Author: Paul Taylor <paul.e.taylor@me.com>

Closes #1614 from trxcllnt/js-fix-html-example and squashes the following commits:

b2a05965 [Paul Taylor] fix JS html FileReader example

itaiin/arrow,wagavulin/arrow,siddharthteotia/arrow,icexelloss/arrow,laurentgo/arrow,wagavulin/arrow,wesm/arrow,itaiin/arrow,wagavulin/arrow,siddharthteotia/arrow,dremio/arrow,laurentgo/arrow,majetideepak/arrow,yufeldman/arrow,siddharthteotia/arrow,apache/arrow,renesugar/arrow,wagavulin/arrow,majetideepak/arrow,majetideepak/arrow,majetideepak/arrow,kou/arrow,xhochy/arrow,wagavulin/arrow,pcmoritz/arrow,pcmoritz/arrow,dremio/arrow,itaiin/arrow,laurentgo/arrow,majetideepak/arrow,pcmoritz/arrow,wesm/arrow,cpcloud/arrow,cpcloud/arrow,laurentgo/arrow,wesm/arrow,kou/arrow,siddharthteotia/arrow,kou/arrow,xhochy/arrow,renesugar/arrow,xhochy/arrow,kou/arrow,siddharthteotia/arrow,wesm/arrow,dremio/arrow,itaiin/arrow,wesm/arrow,xhochy/arrow,yufeldman/arrow,kou/arrow,majetideepak/arrow,renesugar/arrow,apache/arrow,yufeldman/arrow,icexelloss/arrow,icexelloss/arrow,icexelloss/arrow,laurentgo/arrow,dremio/arrow,icexelloss/arrow,itaiin/arrow,dremio/arrow,tebeka/arrow,renesugar/arrow,majetideepak/arrow,pcmoritz/arrow,yufeldman/arrow,cpcloud/arrow,icexelloss/arrow,cpcloud/arrow,cpcloud/arrow,kou/arrow,cpcloud/arrow,wesm/arrow,yufeldman/arrow,tebeka/arrow,siddharthteotia/arrow,laurentgo/arrow,pcmoritz/arrow,renesugar/arrow,laurentgo/arrow,siddharthteotia/arrow,wagavulin/arrow,cpcloud/arrow,yufeldman/arrow,apache/arrow,xhochy/arrow,majetideepak/arrow,xhochy/arrow,apache/arrow,tebeka/arrow,majetideepak/arrow,renesugar/arrow,yufeldman/arrow,yufeldman/arrow,xhochy/arrow,icexelloss/arrow,xhochy/arrow,laurentgo/arrow,pcmoritz/arrow,xhochy/arrow,xhochy/arrow,kou/arrow,apache/arrow,pcmoritz/arrow,dremio/arrow,wagavulin/arrow,icexelloss/arrow,siddharthteotia/arrow,dremio/arrow,tebeka/arrow,siddharthteotia/arrow,pcmoritz/arrow,renesugar/arrow,laurentgo/arrow,renesugar/arrow,dremio/arrow,laurentgo/arrow,kou/arrow,pcmoritz/arrow,majetideepak/arrow,renesugar/arrow,siddharthteotia/arrow,xhochy/arrow,icexelloss/arrow,itaiin/arrow,tebeka/arrow,laurentgo/arrow,itaiin/arrow,wesm/arrow,apache/arrow,icexelloss/arrow,laurentgo/arrow,itaiin/arrow,icexelloss/arrow,tebeka/arrow,itaiin/arrow,renesugar/arrow,itaiin/arrow,laurentgo/arrow,apache/arrow,apache/arrow,majetideepak/arrow,tebeka/arrow,apache/arrow,wagavulin/arrow,icexelloss/arrow,majetideepak/arrow,laurentgo/arrow,yufeldman/arrow,xhochy/arrow,itaiin/arrow,renesugar/arrow,apache/arrow,wesm/arrow,dremio/arrow,cpcloud/arrow,tebeka/arrow,itaiin/arrow,majetideepak/arrow,wesm/arrow,yufeldman/arrow,wagavulin/arrow,pcmoritz/arrow,renesugar/arrow,xhochy/arrow,apache/arrow,kou/arrow,wesm/arrow,cpcloud/arrow,apache/arrow,renesugar/arrow,wagavulin/arrow,dremio/arrow,kou/arrow,kou/arrow,pcmoritz/arrow,tebeka/arrow,cpcloud/arrow,wagavulin/arrow,icexelloss/arrow,tebeka/arrow,yufeldman/arrow,itaiin/arrow,wagavulin/arrow,itaiin/arrow,apache/arrow,xhochy/arrow,siddharthteotia/arrow,kou/arrow,cpcloud/arrow,renesugar/arrow,wesm/arrow,cpcloud/arrow,pcmoritz/arrow,majetideepak/arrow,itaiin/arrow,pcmoritz/arrow,wesm/arrow,pcmoritz/arrow,xhochy/arrow,icexelloss/arrow,majetideepak/arrow,cpcloud/arrow,kou/arrow,pcmoritz/arrow,apache/arrow,renesugar/arrow,wesm/arrow,kou/arrow,dremio/arrow,cpcloud/arrow,laurentgo/arrow,wesm/arrow