chore(ncrypt-js): update README.md

- update and improve README.md file
- remove tsconfig.json from release files
- add weekly download badge

chore(ncrypt-js): add named exports

- add commonjs named exports
- remove redundant dependency crypto

feat(randomStr): add random string generated

- add randomString static method
- remove ncrypt.d.ts file
- add ci.yml file to test on master and pr
- move all functions from utils.ts to ncrypt.ts file
- remove redundant travis.yml file
- refactor source code

chore(workflow): fix workflow

2.0.0

 Release for version v1.0.0