Add PClean datasets and schema and run pclean/pclean on them in the integration test

[ThomasColthurst]

Also, upgrade the integration test to echo the commands being run and (importantly!) fail on any error.

[srvasude]

Is this schema/observation format backwards incompatible with Model 1-4? I feel pretty out of the loop here with this subdirectory / it's relation to models 1-4.

We have a flights/rents dataset checked in for those models (and in particular have several different schema formats which may make more sense for HIRM). Can we migrate those instead (I think it's confusing now that we have pclean-flights* datasets and flights datasets)?

[ThomasColthurst]

Is this schema/observation format backwards incompatible with Model 1-4? I feel pretty out of the loop here with this subdirectory / it's relation to models 1-4.

Nope, the schema format and observation format are both incompatible with Models 1-4. Models 1-4 are relational, whereas these files are tabular -- the observation format is CSV and the schema file is based on PClean.

We have a flights/rents dataset checked in for those models (and in particular have several different schema formats which may make more sense for HIRM). Can we migrate those instead (I think it's confusing now that we have pclean-flights* datasets and flights datasets)?

We can not. We want to maintain the old relational tests, and add new tests for the pclean/pclean program that wants the new formats.

[ThomasColthurst]

PTAL, as I had to add a bug fix for #139 to this pull request in order to get the integration tests to run successfully.