Patch troublesome dependencies:

memb-graphql-api-elixir-1.7-upgrade.patch

diff --git a/lib/graphql/clients/prometheus_clients.ex b/lib/graphql/clients/prometheus_clients.ex
index 37e211f..f41f4ab 100644
--- a/lib/graphql/clients/prometheus_clients.ex
+++ b/lib/graphql/clients/prometheus_clients.ex
@@ -4,6 +4,7 @@ defmodule Graphql.Clients.Prometheus do
   require Prometheus.Metric.Gauge
   require Prometheus.Metric.Histogram
   require Prometheus.Contrib.HTTP
+  require Prometheus.Error
 
   @client_duration_metric_name :http_client_request_duration_microseconds
   @client_inprogress_metric_name :http_client_requests_inprogress
@@ -30,12 +31,10 @@ defmodule Graphql.Clients.Prometheus do
   def observe_duration(service, operation, fun) when is_function(fun, 0) do
     Prometheus.Metric.Gauge.track_inprogress(
       [name: @client_inprogress_metric_name, labels: [service, operation]],
-      fn ->
         Prometheus.Metric.Histogram.observe_duration(
           [name: @client_duration_metric_name, labels: [service, operation]],
-          fun
+          fun.()
         )
-      end
     )
   end
 end
diff --git a/mix.exs b/mix.exs
index cea1305..dd26bf9 100644
--- a/mix.exs
+++ b/mix.exs
@@ -65,7 +65,7 @@ defmodule Graphql.Mixfile do
       {:deferred_config, github: "Financial-Times/deferred_config", override: true},
       {:prometheus_plugs, "~> 1.1"},
       # NB v2.x has breaking changes
-      {:prometheus_ex, "~> 1.4"},
+      {:prometheus_ex, "~> 3.0", override: true},
       {:recon, "~> 2.3"},
       # {:xprof, "~> 1.3"},
       # {:lager_logger, github: "PSPDFKit-labs/lager_logger"},
diff --git a/mix.lock b/mix.lock
index 9c56ea4..5f00c21 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,5 +1,5 @@
 %{
-  "absinthe": {:hex, :absinthe, "1.4.12", "50e7a70088e5896fe3581958f36f6b6bd9e6f36b9626d85db42f1283bbdd5d86", [:mix], [{:dataloader, "~> 1.0.0", [hex: :dataloader, repo: "hexpm", optional: true]}, {:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm"},
+  "absinthe": {:hex, :absinthe, "1.4.13", "81eb2ff41f1b62cd6e992955f62c22c042d1079b7936c27f5f7c2c806b8fc436", [:mix], [{:dataloader, "~> 1.0.0", [hex: :dataloader, repo: "hexpm", optional: true]}, {:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm"},
   "absinthe_plug": {:hex, :absinthe_plug, "1.4.5", "f63d52a76c870cd5f11d4bed8f61351ab5c5f572c5eb0479a0137f9f730ba33d", [:mix], [{:absinthe, "~> 1.4.11", [hex: :absinthe, repo: "hexpm", optional: false]}, {:plug, "~> 1.3.2 or ~> 1.4", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm"},
   "accept": {:hex, :accept, "0.3.3", "548ebb6fb2e8b0d170e75bb6123aea6ceecb0189bb1231eeadf52eac08384a97", [:rebar3], [], "hexpm"},
   "benchee": {:hex, :benchee, "0.13.1", "bd93ca05be78bcb6159c7176230efeda2f724f7ffd485515175ca411dff4893e", [:mix], [{:deep_merge, "~> 0.1", [hex: :deep_merge, repo: "hexpm", optional: false]}], "hexpm"},
@@ -42,8 +42,8 @@
   "plug": {:hex, :plug, "1.6.1", "c62fe7623d035020cf989820b38490460e6903ab7eee29e234b7586e9b6c91d6", [:mix], [{:cowboy, "~> 1.0.1 or ~> 1.1 or ~> 2.4", [hex: :cowboy, repo: "hexpm", optional: true]}, {:mime, "~> 1.0", [hex: :mime, repo: "hexpm", optional: false]}], "hexpm"},
   "poison": {:hex, :poison, "3.1.0", "d9eb636610e096f86f25d9a46f35a9facac35609a7591b3be3326e99a0484665", [:mix], [], "hexpm"},
   "pre_commit": {:hex, :pre_commit, "0.3.4", "e2850f80be8090d50ad8019ef2426039307ff5dfbe70c736ad0d4d401facf304", [:mix], [], "hexpm"},
-  "prometheus": {:hex, :prometheus, "3.5.1", "12139025b942743206a315f31c78d6557dd6848ffde1023f7e93f62ec93352db", [:mix, :rebar3], [], "hexpm"},
-  "prometheus_ex": {:hex, :prometheus_ex, "1.4.1", "5e08decec6f925c296b99eb136b40e8dacdedd9f03553575ee88a38a23ce9601", [:mix], [{:prometheus, "~> 3.4", [hex: :prometheus, repo: "hexpm", optional: false]}], "hexpm"},
+  "prometheus": {:hex, :prometheus, "4.2.0", "06c58bfdfe28d3168b926da614cb9a6d39593deebde648a5480e32dfa3c370e9", [:mix, :rebar3], [], "hexpm"},
+  "prometheus_ex": {:hex, :prometheus_ex, "3.0.3", "5d722263bb1f7a9b1d02554de42e61ea672b4e3c07c3f74e23ce35ab5e111cfa", [:mix], [{:prometheus, "~> 4.0", [hex: :prometheus, repo: "hexpm", optional: false]}], "hexpm"},
   "prometheus_plugs": {:hex, :prometheus_plugs, "1.1.5", "25933d48f8af3a5941dd7b621c889749894d8a1082a6ff7c67cc99dec26377c5", [:mix], [{:accept, "~> 0.1", [hex: :accept, repo: "hexpm", optional: false]}, {:plug, "~> 1.0", [hex: :plug, repo: "hexpm", optional: false]}, {:prometheus_ex, "~> 1.1 or ~> 2.0 or ~> 3.0", [hex: :prometheus_ex, repo: "hexpm", optional: false]}, {:prometheus_process_collector, "~> 1.1", [hex: :prometheus_process_collector, repo: "hexpm", optional: true]}], "hexpm"},
   "ranch": {:hex, :ranch, "1.3.2", "e4965a144dc9fbe70e5c077c65e73c57165416a901bd02ea899cfd95aa890986", [:rebar3], [], "hexpm"},
   "recon": {:hex, :recon, "2.3.6", "2bcad0cf621fb277cabbb6413159cd3aa30265c2dee42c968697988b30108604", [:rebar3], [], "hexpm"},