Add support for the Trivy JSON report format

[denniebouman]

Describe the solution you'd like
Add support for the Trivy JSON report format:
https://aquasecurity.github.io/trivy/v0.45/docs/configuration/reporting/

Additional context

[
  {
    "Target": "php-app/composer.lock",
    "Vulnerabilities": null
  },
  {
    "Target": "node-app/package-lock.json",
    "Vulnerabilities": [
      {
        "VulnerabilityID": "CVE-2018-16487",
        "PkgName": "lodash",
        "InstalledVersion": "4.17.4",
        "FixedVersion": "\u003e=4.17.11",
        "Title": "lodash: Prototype pollution in utilities function",
        "Description": "A prototype pollution vulnerability was found in lodash \u003c4.17.11 where the functions merge, mergeWith, and defaultsDeep can be tricked into adding or modifying properties of Object.prototype.",
        "Severity": "HIGH",
        "References": [
          "https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-16487",
        ]
      }
    ]
  },
  {
    "Target": "trivy-ci-test (alpine 3.7.1)",
    "Vulnerabilities": [
      {
        "VulnerabilityID": "CVE-2018-16840",
        "PkgName": "curl",
        "InstalledVersion": "7.61.0-r0",
        "FixedVersion": "7.61.1-r1",
        "Title": "curl: Use-after-free when closing \"easy\" handle in Curl_close()",
        "Description": "A heap use-after-free flaw was found in curl versions from 7.59.0 through 7.61.1 in the code related to closing an easy handle. ",
        "Severity": "HIGH",
        "References": [
          "https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-16840",
        ]
      },
      {
        "VulnerabilityID": "CVE-2019-3822",
        "PkgName": "curl",
        "InstalledVersion": "7.61.0-r0",
        "FixedVersion": "7.61.1-r2",
        "Title": "curl: NTLMv2 type-3 header stack buffer overflow",
        "Description": "libcurl versions from 7.36.0 to before 7.64.0 are vulnerable to a stack-based buffer overflow. ",
        "Severity": "HIGH",
        "References": [
          "https://curl.haxx.se/docs/CVE-2019-3822.html",
          "https://lists.apache.org/thread.html/8338a0f605bdbb3a6098bb76f666a95fc2b2f53f37fa1ecc89f1146f@%3Cdevnull.infra.apache.org%3E"
        ]
      },
      {
        "VulnerabilityID": "CVE-2018-16839",
        "PkgName": "curl",
        "InstalledVersion": "7.61.0-r0",
        "FixedVersion": "7.61.1-r1",
        "Title": "curl: Integer overflow leading to heap-based buffer overflow in Curl_sasl_create_plain_message()",
        "Description": "Curl versions 7.33.0 through 7.61.1 are vulnerable to a buffer overrun in the SASL authentication code that may lead to denial of service.",
        "Severity": "HIGH",
        "References": [
          "https://github.com/curl/curl/commit/f3a24d7916b9173c69a3e0ee790102993833d6c5",
        ]
      },
      {
        "VulnerabilityID": "CVE-2018-19486",
        "PkgName": "git",
        "InstalledVersion": "2.15.2-r0",
        "FixedVersion": "2.15.3-r0",
        "Title": "git: Improper handling of PATH allows for commands to be executed from the current directory",
        "Description": "Git before 2.19.2 on Linux and UNIX executes commands from the current working directory (as if '.' were at the end of $PATH) in certain cases involving the run_command() API and run-command.c, because there was a dangerous change from execvp to execv during 2017.",
        "Severity": "HIGH",
        "References": [
          "https://usn.ubuntu.com/3829-1/",
        ]
      },
      {
        "VulnerabilityID": "CVE-2018-17456",
        "PkgName": "git",
        "InstalledVersion": "2.15.2-r0",
        "FixedVersion": "2.15.3-r0",
        "Title": "git: arbitrary code execution via .gitmodules",
        "Description": "Git before 2.14.5, 2.15.x before 2.15.3, 2.16.x before 2.16.5, 2.17.x before 2.17.2, 2.18.x before 2.18.1, and 2.19.x before 2.19.1 allows remote code execution during processing of a recursive \"git clone\" of a superproject if a .gitmodules file has a URL field beginning with a '-' character.",
        "Severity": "HIGH",
        "References": [
          "http://www.securitytracker.com/id/1041811",
        ]
      }
    ]
  },
  {
    "Target": "python-app/Pipfile.lock",
    "Vulnerabilities": null
  },
  {
    "Target": "ruby-app/Gemfile.lock",
    "Vulnerabilities": null
  },
  {
    "Target": "rust-app/Cargo.lock",
    "Vulnerabilities": null
  }
]