Resolve subtle lint issues
Resolve subtle lint issues

The body of `if` statements should be surrounded with braces.  Now the
lint check doesn't stop the build process from executing the tests.

Also, while using `return` to stop `if` execution results in less code,
I side with the team that favors explicitly using `else` statements.

JohnnyEstilles/node-mocks-http,marneborn/node-mocks-http,mtimofiiv/node-mocks-http,marneborn/node-mocks-http,vgatto/node-mocks-http,XescuGC/node-mocks-http,dgileadi/node-mocks-http