CLC-3565, rspec v3 upgrade - spec_helper.rb to raise errors for deprecated, etc.

https://jira.ets.berkeley.edu/jira/browse/CLC-3565

spec_helper configs so deprecation warnings become errors. We also get:
+ infer_spec_type_from_file_location!
+ mocks.yield_receiver_to_any_instance_implementation_blocks
+ mocks.patch_marshal_to_support_partial_doubles

@christianv @raydavis @ctweney That will go away on next PR, in which version numbers will jump to 3.1.0