Large refactoring/rewrite

[leifg]

Here are the changes:

• add MIT License (kept the original copyright notices)
• bump API version to 27.0
• separate HTTP and CSV handling
• correctly handle Array values as multi picklists (see #10)
• add testing and code metrics (travis-ci, codeclimate, coveralls)
• rename create to insert (to make it consistent with the salesforce bulk API naming)
• refactor behaviour of wait flag

Still WIP, let me know what you think

[leifg]

As there is no reaction to this pull requet. I released it under a different name (Copyright and Commit logs have been retained)

https://github.com/propertybase/executrix