Updates to test on different Node.js versions and removes iojs
Updates to test on different Node.js versions and removes iojs

squiggle-lang/squiggle-lang,wavebeem/squiggle,wavebeem/squiggle,saikobee/expr-lang,saikobee/squiggle,saikobee/expr-lang,squiggle-lang/squiggle-lang,saikobee/squiggle,saikobee/expr-lang,squiggle-lang/squiggle-lang,saikobee/squiggle,wavebeem/squiggle