- changed SendExperimentFile, now it supports arbitrary files, but it doesn't trigger compilation like before
 - added DeleteExperimentFile
 - added CompileExprimentFile
 - added SendExperimentArgs
 - related unittests added
 - unittest working directory changed
 - googletest are stored in code tree now

APIs:
- added CopmileExperimentFile
- added DeleteExperimentFile
- added SendExperimentArgs
- changed behavior of SendExperimentFile
- deleted GetStatus

Docs:
- added example.cpp to show how to use API

- fixed high voltage and high voltage slew rate data conversion bug
- check response error code
- adjusted unittest

Now after sending the experiment file, the application waits for the compilation log

- corresponding tests are updated