Update dependency pg to v1.6.0

Gemfile.lock

@@ -230,7 +230,11 @@ GEM
     parser (3.3.8.0)
       ast (~> 2.4.1)
       racc
-    pg (1.5.9)
+    pg (1.6.0)
+    pg (1.6.0-aarch64-linux)
+    pg (1.6.0-arm64-darwin)
+    pg (1.6.0-x86_64-darwin)
+    pg (1.6.0-x86_64-linux)
     pluck_to_hash (1.0.2)
       activerecord (>= 4.0.2)
       activesupport (>= 4.0.2)
@@ -576,7 +580,11 @@ CHECKSUMS
   ostruct (0.6.2) sha256=6d7302a299e400a2c248d6ce0dad18fc3a5714e8096facc25ffd0c54ee57cfc0
   parallel (1.27.0) sha256=4ac151e1806b755fb4e2dc2332cbf0e54f2e24ba821ff2d3dcf86bf6dc4ae130
   parser (3.3.8.0) sha256=2476364142b307fa5a1b1ece44f260728be23858a9c71078e956131a75453c45
-  pg (1.5.9) sha256=761efbdf73b66516f0c26fcbe6515dc7500c3f0aa1a1b853feae245433c64fdc
+  pg (1.6.0) sha256=26ea1694e4ed2e387a8292373acbb62ff9696d691d3a1b8b76cf56eb1d9bd40b
+  pg (1.6.0-aarch64-linux) sha256=23690afbe8d4374a399a6ff683e2aee713002e27767b3e40be0c112d90a9a648
+  pg (1.6.0-arm64-darwin) sha256=1ee9bf9858a532020e69483a0939b51eff52b369ee6cb2ce267c4d06e211f3e6
+  pg (1.6.0-x86_64-darwin) sha256=b0f631bd96f914a4a54267d2fb33a25caa7e6004670734f517b04e82b6a74f06
+  pg (1.6.0-x86_64-linux) sha256=5e0054765ab94f80152cbfbf986da54348b145e436663579df3d1e1d667d5e39
   pluck_to_hash (1.0.2) sha256=1599906239716f98262a41493dd7d4cb72e8d83ad3d76d666deacfc5de50a47e
   pp (0.6.2) sha256=947ec3120c6f92195f8ee8aa25a7b2c5297bb106d83b41baa02983686577b6ff
   prettyprint (0.2.0) sha256=2bc9e15581a94742064a3cc8b0fb9d45aae3d03a1baa6ef80922627a0766f193