v2.1.0

• Update Grafana default version to 2.1.1
• Make sure upgrading via deb file don't fail on configuration conflict #74
• Ensure installing a new version trigger a server restart
• Add packages checksum to ensure expected file and prevent unecessary re-download (see warnings section below)
• Installation package file only if present and/or modified (@arifcse019) #73
• Fix start service making it just be restarted at the end of the configuration (@HelioCampos) #71
• Improve error messages during dashboard creation #64
• Update ServerSpec test to check :stderr for curl output

warning

When using the default's file installation, we've added checksum for package files
if you set the grafana version to something different than the default you will
also need set the checksum for the package you're expecting to use:

# Example if your Grafana version is different from the cookbook default
node['grafana']['version'] = '2.1.0'
# For debian platform family
node['grafana']['file']['checksum']['deb'] = 'b824c8358ff07f76f0d9eb35e9441f6f9e591819ad8bc70db4b0c904a8e7130e'
# For rhel platform family
node['grafana']['file']['checksum']['rpm'] = '1b436b286bd464e65eeb2a9b393da0986569fe483e1053b01c092b2e590d8399'