Fix all lint warnings except todo comments (including a bug!)

src/components/audio-trimmer/audio-trimmer.jsx

src/components/meter/meter.jsx

src/components/record-modal/recording-step.jsx

src/containers/audio-trimmer.jsx

src/lib/audio/audio-buffer-player.js

src/lib/audio/audio-effects.js

src/lib/audio/effects/robot-effect.js

src/lib/audio/shared-audio-context.js

src/lib/blocks.js

src/lib/monitor-adapter.js

src/lib/opcode-labels.js

test/helpers/selenium-helpers.js

test/unit/util/audio-util.test.js