Revert "Revert "Merge pull request #72 from stan-dev/feature/add_command_test_to_unit_tests""

This reverts commit 41582f92b2922b391879a166f7776933a7f330af.
adding command test to test-unit target
Merge branch 'develop' into feature/add_command_test_to_unit_tests
adding default constructors to the stan_csv_reader's structures.

Under Windows, some of the structure members are not being set to default values causing unexpected behavior
adding a dependency on the test/models/command test for test-unit
Merge branch 'develop' into feature/add_command_test_to_unit_tests

Conflicts:
	src/stan/io/stan_csv_reader.hpp
Merge pull request #108 from stan-dev/feature/add_command_test_to_unit_tests

Feature/add command test to unit tests