Get position to fix writeMicroseconds.
Always use build_cmd_str.
Remove trailing whitespace and use consistent spacing.
Remove unused attribute.
Refactor Arduino and add sr argument to constructor to enable testing.
Add pure-python tests.
Fix port detection bugs and add more ports for linux.
Only close serial port if not already closed.
Add another test to explicitly connect to a serial port.
Use logging instead of print statements.
Setup logging during testing.
Force the user to enter a port during interactive testing.
Update documentation for shiftIn, shiftOut and additional tests.
Merge pull request #5 from ianjosephwilson/master

Refactoring and testing.