v0.4.1: specify http timeout on the configuration file (#5)

• moved config.go to its own package so I can reuse it in main and in collectors
• allow configuration of HTTP timeout
• allow configuration of HTTP insecure flag
• Add more labels for systems and drives. These labels are useful for alerting and ticket creation.
• Additional metric for drive failure detection

BREAKING CHANGE:

• rename metrics votage to voltage

v0.4

• additional labels on some metrics
• added predicted failure metric for drives
• allow regex format for host entries on config.yml

logging enhancements

• logging enhancements