json support
examples use json by default
Merge branch 'feature/json-data' into develop
-- stands for stdin for both --keys and --json
dont repeat yourself
examples for the use of stdin with --json
Merge branch 'feature/read-stdin' into develop
all ready for 0.3
Merge branch 'release/0.3'
Merge tag '0.3' into develop

Release notes:

- json support
- read from stdin
- jinja2 support