fix disks and servers live tests
remove some test output, add size_gb as a required field for disk creation
rewrite the way model is waited in live tests
fix asynchronious disks collection tests
fix object test (it already was shared object with such name somewhere)
fix live tests for google engine
add new line to the end of google_tests_helper.rb
fix 1.8.7 compatibility
merge with master
Merge pull request #2995 from allomov/google-live-tests

[google|tests] Fix disks and servers live tests