varchar with no length == NullType

On redshift, a variable character field with no lenth
attached is considered a nulltype field.
updating version for release
first additions for testing
adding sqlalchemy as a dependency
removing pypy
slightly better pinning
adding travis image
correct formatting for rst
Added UnloadFromSelect and associated tests. Also added build/ to .gitignore

Signed-off-by: Jason Myers <jason@jasonamyers.com>
Added Documentation Strings

Signed-off-by: Jason Myers <jason@jasonamyers.com>
Simplied tests

Signed-off-by: Jason Myers <jason@jasonamyers.com>
Merge pull request #1 from jasonamyers/master

Added UnloadFromSelect and associated tests. Also added build/ to .gitignore
updating version for release