more knitr fixes
more knitr fixes

SepidehD/dev-earthlab-site,SepidehD/dev-earthlab-site,SepidehD/dev-earthlab-site,earthlab/dev-earthlab-site,earthlab/dev-earthlab-site,SepidehD/dev-earthlab-site,earthlab/dev-earthlab-site,earthlab/dev-earthlab-site