v0.3.0

• configuration keys ("sources", "events") are not mandatory anymore (53c0dd7)
• calendar builder configuration is now optional (0b741b8)
• event sources, calendar events and converters can now be created by passing a classname (c655dae d94da67 b0b296b)
• fix converter instances cache (0a2d598)
• improved handling of services by internal container (4348960)
• added and updated some unit tests
• update vendor dependencies (54526b1)
• update documentation