Support ignore CveIDs in config

[kotakanbe]

Example: IgnoreCves

Define ignoreCves in config if you don't want to report(slack, mail, text...) specific CVE IDs. But these ignoreCves will be output to JSON file like below.

• config.toml

[default]
ignoreCves = ["CVE-2016-6313"]

[servers.bsd]
host     = "192.168.11.11"
user     = "kanbe"
ignoreCves = ["CVE-2016-6314"]

• bsd.json

[
  {
    "ServerName": "bsd",
    "Family": "FreeBSD",
    "Release": "10.3-RELEASE",
    "IgnoredCves" : {
      "CveDetail" : {
        "CVE-2016-6313",
        ...
      },
      "CveDetail" : {
        "CVE-2016-6314",
        ...
      },
    }
  }
]