Add, edit & delete secrets. Overall UX, technical and security improvements

This release adds about 100 fresh commits to the project. See what features, changes in documentation and technical improvements they bring:

Features 💰

• Environment test: verify that gopass and GPG setup works and Gopass UI can access it 🚦
• Add new secrets: including password generator and strength indication ➕
• Edit secret functionality on secret-detail-page ✏️
• Delete secret functionality on secret-detail-page 🗑
• Loading indicator on secret-detail-page ⏲

Documentation ✍️

• Extended the development documentation
• Documented all supported platforms and packages
• Documented instructions to create a new release on Github

Technical improvements 🛠

• Implemented security recommendations of Electron 🛡
• No more global state handling, got rid of Redux dependencies. Switching to pure functions and React Hooks where possible 🎉
• Upgrade Electron from 2.0.0 to latest version 5.0.0, meaning we upgraded from Chromium 61.x up to Chromium 73.x – it was about time 💥
• CI pipeline using TravisCI 🚢
• Portage package available via emerge on Gentoo, thanks to @danielcb 🙌

Try it out, have fun and please provide us your feedback. You are always welcome in the Github issues.