Fixes for 21 different rubocop cop violations

[alexjfisher]

These are all rubocop autofixes but done as individual commits and reviewed.
With each fix, care is taken to not introduce (or reintroduce) other violations.

This PR takes the total violation count down from 2256 to 1375.
The last commit was the result of running.

rubocop -D -S -E --only Layout/SpaceAroundBlockParameters,Layout/EmptyLinesAroundBlockBody,Style/StringLiterals,Layout/SpaceAroundOperators,Style/TrailingCommaInLiteral,Layout/SpaceAfterComma,Layout/LeadingCommentSpace,Layout/CaseIndentation,Style/RedundantReturn,Style/CollectionMethods,Style/RedundantParentheses,Style/AndOr,Layout/AlignHash,Style/BlockDelimiters,Style/NegatedIf,Style/MultilineIfThen,Lint/UnusedBlockArgument,Layout/ExtraSpacing,Style/ParenthesesAroundCondition,Style/IfUnlessModifier,RSpec/ExampleWording,Style/ParenthesesAroundCondition,Layout/EmptyLines,Style/MethodCallWithoutArgsParentheses,Layout/SpaceInsideBlockBraces,Layout/SpaceInsideHashLiteralBraces -a

This PR is hopefully a good compromise between a separate PR per fix and a PR too big for review. There are still more fixes (auto fixable and those that can't be) needed.