Python 3 compatability fix

In Python 3 string literals are str, and not bytes, so `DictAttribute.__set___` would pass the wrong type of argument to the C functino `drmaa_set_vector_attribute`. This simple change encodes strings to bytes with the system default encoding. Since you can called `.encode()` on byte strings in Python 2.x without side-effect, this simple change should work with both.
Merge pull request #1 from dan-blanchard/patch-1

Python 3 compatability fix
Switch to using new style format strings instead of old ones.
Merge pull request #2 from dan-blanchard/patch-1

Switch to using new style format strings instead of old ones.
Made all constants explicit byte strings since they're frequently passed to C
Merge branch 'patch-1'
PEP8 fixes all over the place.
Yet another work around to work with Python 3.
Merge branch 'patch-1'
Fix missing import
Add .encode() to string_vector to get around the whole problem of needing to pass bytes in the first place.
Made .encodes conditional, in case someone explicitly passes bytes in Python 3
Massive amount of PEP8 compliance clean up.
More cleaning/refactoring. I believe I've now standardized it so that all functions that take strings take unicode strings.
Fix a NoneType issue with py_drmaa_init
Add Travis unit test stuff.
Added missing smp bit to pe_list line of queue_template.
Swap order of creating queue and parallel environment to fix crash.
Moved tests into separate directory and cleaned them up a bit.
Added missing import to testwrap.py