fix: package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/npm:mime:20170907

Latest report for feedhenry/fh-gridfs:
https://snyk.io/test/github/feedhenry/fh-gridfs

package.json

@@ -7,9 +7,9 @@
     "version": "sed -i.bak \"s/sonar.projectVersion=.*/sonar.projectVersion=${npm_package_version}/\" sonar-project.properties && rm sonar-project.properties.bak && git add sonar-project.properties"
   },
   "main": "lib/gridFileManager.js",
-  "repository" : {
-    "type" : "git",
-     "url" : "git@github.com:feedhenry/fh-gridfs.git"
+  "repository": {
+    "type": "git",
+    "url": "git@github.com:feedhenry/fh-gridfs.git"
   },
   "bugs": {
     "url": "https://github.com/feedhenry/fh-gridfs/issues"
@@ -24,7 +24,7 @@
     "base64-stream": "0.1.2",
     "gridfs-stream": "0.4.0",
     "lodash": "2.1.0",
-    "mime": "1.2.11",
+    "mime": "1.4.1",
     "mongodb": "2.1.18",
     "rimraf": "2.2.2",
     "usage": "^0.7.1"