Fix for dirname function returning "\"

For paths like "/myFile.txt" dirname returns "\" causing the API call to fail.
Merge pull request #14 from lucassp/master

Fix for dirname returning "\"
Update tests/setup

Change location of php binary in shebang
Merge pull request #15 from kachkaev/master

Fix location of PHP binary in tests/setup shebang
do not modify curl args
fixes tests with Curl backend
re-add cainfo curl opt
Merge pull request #18 from BrummbQ/master

dropbox create folder curl args