Release v0.3.0

qrcode 0.3.0

• Add qr_vcard() to generate QR codes for a vCard.
• Add qr_sepa() to generate QR codes for SEPA payments.
• Add qr_location() to generate QR codes for locations.
• generate_svg() now escapes the special characters &, ', ", <, >.
  Fixes #19 reported by @kaveelim.