v0.3.0

Replay v0.3.0

Diff since v0.2.1

Merged pull requests:

• activate project (#20) (@terasakisatoshi)
• add example that analyzes the iris dataset (#21) (@terasakisatoshi)
• Demonstrate pca (#22) (@terasakisatoshi)
• Support instruction with multiple lines (#24) (@terasakisatoshi)
• Prepare release v0.3.0 (#25) (@terasakisatoshi)