Merge pull request #4 from thebioengineer/improvement/install_r_lib

add ability to specify version of R package to install, and improve processing of multi-line dockerfiles

Merge pull request #3 from thebioengineer/add_tests

remove incorrect setup test

reformatting and remove incorrect setup test

remove docker_start from documentation

remove docker_start function

remove 'is_local_image' function

add port type testing

add methods for specifying port type

add methods for testing docker_connection

move docker_* controls to this test file

add code_cov comments

Merge pull request #2 from thebioengineer/add_tests

remove appveyor yaml changes