Build: Bake LaTex into postgres9.6 docker image
Build: Bake LaTex into postgres9.6 docker image

Add commented code in the Dockerfile for generating postgres
image that has latex baked into it. The guideline specified is to
tag the image with latex as 'LaTex', so that we don't bulk up the
existing 'latest' and 'jenkins' images.

Closes #185

orhankislal/incubator-madlib,orhankislal/incubator-madlib,apache/incubator-madlib,njayaram2/madlib,njayaram2/madlib,orhankislal/incubator-madlib,madlib/madlib,iyerr3/incubator-madlib,hpandeycodeit/incubator-madlib,hpandeycodeit/incubator-madlib,iyerr3/incubator-madlib,apache/incubator-madlib,madlib/madlib,orhankislal/madlib,apache/incubator-madlib,iyerr3/incubator-madlib,orhankislal/madlib,iyerr3/incubator-madlib,madlib/madlib,apache/incubator-madlib,madlib/madlib,hpandeycodeit/incubator-madlib,apache/incubator-madlib,njayaram2/madlib,njayaram2/incubator-madlib,njayaram2/madlib,orhankislal/madlib,orhankislal/madlib,njayaram2/incubator-madlib,orhankislal/madlib,madlib/madlib,iyerr3/incubator-madlib,orhankislal/incubator-madlib,orhankislal/incubator-madlib,njayaram2/madlib,njayaram2/incubator-madlib,njayaram2/incubator-madlib,njayaram2/incubator-madlib,hpandeycodeit/incubator-madlib,hpandeycodeit/incubator-madlib