switch from DataStreams to Tables

[ExpandingMan]

This is a duplicate of #46. I have made several fixes so that tests now pass and updated Travis and Appveyor. Making a new PR was just easier than me figuring out how to update the existing one.

Thanks again to @quinnj for having made this. I think the only reason it got ignored so long was because JavaCall was not working until 1.3.

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@fe072f6). Click here to learn what that means.
The diff coverage is 64.28%.

@@            Coverage Diff            @@
##             master      #51   +/-   ##
=========================================
  Coverage          ?   69.07%           
=========================================
  Files             ?        3           
  Lines             ?      152           
  Branches          ?        0           
=========================================
  Hits              ?      105           
  Misses            ?       47           
  Partials          ?        0

Impacted Files	Coverage Δ
src/JDBC.jl	70% <ø> (ø)
src/tables.jl	74.28% <64.28%> (ø)

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[ExpandingMan]

Suggest we merge and tag this quite quickly as the package is essentially broken without it.

Will do this myself tomorrow unless there are any concerns.