Address rspec deprecation warnings.
Address ruby warnings.

/Users/myron/code/rspec-dev/repos/rspec-expectations/spec/rspec/matchers/has_spec.rb:61: warning: `+' after local variable or literal is interpreted as binary operator
/Users/myron/code/rspec-dev/repos/rspec-expectations/spec/rspec/matchers/has_spec.rb:61: warning: even though it seems like unary operator
Refactor: one less method call per expectation expression.
Issue deprecation for block expectations against non-block matchers.
Merge pull request #535 from rspec/deprecation-for-supports-block-expectations

Deprecation for supports block expectations