v1.2.4

• chore: Modify types. e987f85
• Upgrade devDependencies. a795031
• Remove npm ignore file. 35b606b
• Upgrade jest@24.8.0 56033ae
• Add prepare script. 470f2cf
• Fix type issue. c859f65
• Add .gitattributes 69b57d6
• Add coveralls badges. de193ba