Added dockerfile and sh script to install TFODAPI (TF v 1.15) on Azure Ubuntu 16.04 DSVM

[rosswin]

I added two files that allow easy installation of TFODAPI w/ TF 1.15 on an Azure Ubuntu 16.04 DSVM. Both of the files are modified copies of the existing TFODAPI w/ TF 1.12 dockerfile and sh scripts.

I found that TF 1.15 is a much smoother experience. I was hitting memory errors on computationally expensive models using TF v1.2, even using batch sizes of 1 and small images. I haven't had any issues since making the switch to TF 1.15. My choice of TF 1.15 came from a lot of research, with many recommendations from issues such as this one.

This may not be super useful in the long run. I see that Azure has 18.04 DSVMs out for testing. Also, I read somewhere that TFODAPI will eventually move to TF 2.0. However, in the meantime, it may help someone!

[msftclas]

All CLA requirements met.

[yangsiyu007]

Thank you @rosswin and also for making them separate from the existing ones! I'll try this out next time.