step 1: Test reading some simple nested collections.

step 1: Test reading some simple nested collections.

These tests are intended to catch the cases where the routine for
reading a list, vector, or hashmap fails to consume the trailing token
(')', ']', or '}' as the case may be) from the input.  None of the
existing step 1 tests detected this, and I only found it by playing
around in the REPL.