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

vendor/github.com/prometheus/procfs/fixtures/buddyinfo/short/buddyinfo

@@ -0,0 +1,3 @@
+Node 0, zone
+Node 0, zone
+Node 0, zone

vendor/github.com/prometheus/procfs/fixtures/buddyinfo/sizemismatch/buddyinfo

@@ -0,0 +1,3 @@
+Node 0, zone      DMA      1      0      1      0      2      1      1      0      1      1      3 
+Node 0, zone    DMA32    759    572    791    475    194     45     12      0      0      0      0      0
+Node 0, zone   Normal   4381   1093    185   1530    567    102      4      0      0      0

vendor/github.com/prometheus/procfs/fixtures/buddyinfo/valid/buddyinfo

@@ -0,0 +1,3 @@
+Node 0, zone      DMA      1      0      1      0      2      1      1      0      1      1      3 
+Node 0, zone    DMA32    759    572    791    475    194     45     12      0      0      0      0 
+Node 0, zone   Normal   4381   1093    185   1530    567    102      4      0      0      0      0 

vendor/github.com/prometheus/procfs/fixtures/fs/xfs/stat

@@ -0,0 +1,23 @@
+extent_alloc 92447 97589 92448 93751
+abt 0 0 0 0
+blk_map 1767055 188820 184891 92447 92448 2140766 0
+bmbt 0 0 0 0
+dir 185039 92447 92444 136422
+trans 706 944304 0
+ig 185045 58807 0 126238 0 33637 22
+log 2883 113448 9 17360 739
+push_ail 945014 0 134260 15483 0 3940 464 159985 0 40
+xstrat 92447 0
+rw 107739 94045
+attr 4 0 0 0
+icluster 8677 7849 135802
+vnodes 92601 0 0 0 92444 92444 92444 0
+buf 2666287 7122 2659202 3599 2 7085 0 10297 7085
+abtb2 184941 1277345 13257 13278 0 0 0 0 0 0 0 0 0 0 2746147
+abtc2 345295 2416764 172637 172658 0 0 0 0 0 0 0 0 0 0 21406023
+bmbt2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+ibt2 343004 1358467 0 0 0 0 0 0 0 0 0 0 0 0 0
+fibt2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+qm 0 0 0 0 0 0 0 0
+xpc 399724544 92823103 86219234
+debug 0