Updating server dependancies. Also adding github.com/jaytaylor/html2text and gopkg.in/gomail.v2 (#5748)

glide.yaml

@@ -4,6 +4,7 @@ import:
 - package: github.com/alecthomas/log4go
 - package: github.com/dgryski/dgoogauth
 - package: github.com/disintegration/imaging
+  version: v1.0.0
 - package: github.com/go-gorp/gorp
   version: 0c9bc0918534d133cedb439a24adc7cbe66e4a9d
 - package: github.com/go-ldap/ldap
@@ -79,3 +80,6 @@ import:
 - package: github.com/dyatlov/go-opengraph
   subpackages:
   - opengraph
+- package: github.com/jaytaylor/html2text
+- package: gopkg.in/gomail.v2
+  version: 2.0.0