Remove usage of deprecated implicit block expectation from specs

[andrehjr]

For example:

  The implicit block expectation syntax is deprecated, you should pass a block rather than an argument to `expect` to use the provided block expectation matcher or the matcher must implement `supports_value_expectations?`. e.g  `expect { value }.to raise Exception` not `expect(value).to raise Exception`

Also configured rspec to raise deprecations as errors.