Make option for output to be ggmcmc ready

[mhtess]

Output will need to be modified from the current setup to

rs.samp<- data_frame(Iteration = seq(1,100000),
                     Chain = 1,
                     Parameter = factor("b"),
                     value = histToSamples(rs, 100000))

attr(rs.samp, "nChains")<- 1
attr(rs.samp, "nParameters")<- 1
attr(rs.samp, "nIterations")<- 100000
attr(rs.samp, "nBurnin")<- 0
attr(rs.samp, "nThin")<- 0
attr(rs.samp, "description")<- "myBeta"

To first address this, we should have this form of output as an option (not necessarily default)

[mhtess]

Note, this is so we can take advantage of the ggmcmc package