Merge branch 'avatar-circles' into 'master'

Fix sizing of avatar circles; add border

* Adds border to group and project avatars
* Fixes cut-off circles
![Screen_Shot_2016-12-20_at_8.25.12_AM](/uploads/24e0eedf001f230300a316c504af59d4/Screen_Shot_2016-12-20_at_8.25.12_AM.png)
![Screen_Shot_2016-12-20_at_8.24.59_AM](/uploads/23450bf1f99b8075a043dd5512185e91/Screen_Shot_2016-12-20_at_8.24.59_AM.png)
Closes #25733

See merge request !8194

app/assets/stylesheets/framework/avatar.scss

@@ -64,7 +64,7 @@
   &.s32 { font-size: 20px; line-height: 30px; }
   &.s40 { font-size: 16px; line-height: 38px; }
   &.s60 { font-size: 32px; line-height: 58px; }
-  &.s70 { font-size: 34px; line-height: 68px; }
+  &.s70 { font-size: 34px; line-height: 70px; }
   &.s90 { font-size: 36px; line-height: 88px; }
   &.s110 { font-size: 40px; line-height: 108px; font-weight: 300; }
   &.s140 { font-size: 72px; line-height: 138px; }

app/assets/stylesheets/pages/projects.scss

@@ -93,7 +93,6 @@
   .group-avatar {
     float: none;
     margin: 0 auto;
-    border: none;
 
     &.identicon {
       border-radius: 50%;