Update example projects to use tensorflow 2.0

[umesh-timalsina]

deepforge-dev/deepforge-keras#180 adds support for tensorflow2.0 in deepforge-keras. It might be nice to test the example projects here with the branch as well as update the projects here after it is merged.

[brollb]

The data for Redshift-Tutorial is not available (not sure what credentials should be used). Reached out to @KyleAMoore but this is blocking this in the meantime.