implement Stack and Queue with native list container

Signed-off-by: Joshua Rubin <joshua@rubixconsulting.com>
add a priority queue implementation

Signed-off-by: Joshua Rubin <joshua@rubixconsulting.com>
complete test coverage of errors, Int and String types

Signed-off-by: Joshua Rubin <joshua@rubixconsulting.com>
rearrange packages

Signed-off-by: Joshua Rubin <joshua@rubixconsulting.com>