diff --git a/package.json b/package.json
index 7c70332..65151ac 100644
--- a/package.json
+++ b/package.json
@@ -22,7 +22,7 @@
     "fhir-errors": "^1.0.0"
   },
   "devDependencies": {
-    "codecov": "3.0.2",
+    "codecov": "3.2.0",
     "eslint": "4.19.1",
     "eslint-config-prettier": "2.9.0",
     "eslint-plugin-prettier": "2.6.0",
diff --git a/yarn.lock b/yarn.lock
index b517e4b..670211d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -22,6 +22,12 @@ acorn@^5.5.0:
   version "5.5.3"
   resolved "https://registry.yarnpkg.com/acorn/-/acorn-5.5.3.tgz#f473dd47e0277a08e28e9bec5aeeb04751f0b8c9"
 
+agent-base@^4.1.0:
+  version "4.2.1"
+  resolved "https://registry.yarnpkg.com/agent-base/-/agent-base-4.2.1.tgz#d89e5999f797875674c07d87f260fc41e83e8ca9"
+  dependencies:
+    es6-promisify "^5.0.0"
+
 ajv-keywords@^2.1.0:
   version "2.1.1"
   resolved "https://registry.yarnpkg.com/ajv-keywords/-/ajv-keywords-2.1.1.tgz#617997fc5f60576894c435f940d819e135b80762"
@@ -85,7 +91,7 @@ argparse@^1.0.7:
   dependencies:
     sprintf-js "~1.0.2"
 
-argv@0.0.2:
+argv@^0.0.2:
   version "0.0.2"
   resolved "https://registry.yarnpkg.com/argv/-/argv-0.0.2.tgz#ecbd16f8949b157183711b1bda334f37840185ab"
 
@@ -424,13 +430,15 @@ code-point-at@^1.0.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/code-point-at/-/code-point-at-1.1.0.tgz#0d070b4d043a5bea33a2f1a40e2edb3d9a4ccf77"
 
-codecov@3.0.2:
-  version "3.0.2"
-  resolved "https://registry.yarnpkg.com/codecov/-/codecov-3.0.2.tgz#aea43843a5cd2fb6b7e488b2eff25d367ab70b12"
+codecov@3.2.0:
+  version "3.2.0"
+  resolved "https://registry.yarnpkg.com/codecov/-/codecov-3.2.0.tgz#4465ee19884528092d8c313e1f9e4bdc7d3065cd"
   dependencies:
-    argv "0.0.2"
-    request "^2.81.0"
-    urlgrey "0.4.4"
+    argv "^0.0.2"
+    ignore-walk "^3.0.1"
+    js-yaml "^3.12.0"
+    teeny-request "^3.7.0"
+    urlgrey "^0.4.4"
 
 collection-visit@^1.0.0:
   version "1.0.0"
@@ -633,6 +641,16 @@ error-ex@^1.2.0:
   dependencies:
     is-arrayish "^0.2.1"
 
+es6-promise@^4.0.3:
+  version "4.2.5"
+  resolved "https://registry.yarnpkg.com/es6-promise/-/es6-promise-4.2.5.tgz#da6d0d5692efb461e082c14817fe2427d8f5d054"
+
+es6-promisify@^5.0.0:
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/es6-promisify/-/es6-promisify-5.0.0.tgz#5109d62f3e56ea967c4b63505aef08291c8a5203"
+  dependencies:
+    es6-promise "^4.0.3"
+
 escape-string-regexp@^1.0.2, escape-string-regexp@^1.0.3, escape-string-regexp@^1.0.5:
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/escape-string-regexp/-/escape-string-regexp-1.0.5.tgz#1b61c0562190a8dff6ae3bb2cf0200ca130b86d4"
@@ -1069,10 +1087,23 @@ http-signature@~1.2.0:
     jsprim "^1.2.2"
     sshpk "^1.7.0"
 
+https-proxy-agent@^2.2.1:
+  version "2.2.1"
+  resolved "https://registry.yarnpkg.com/https-proxy-agent/-/https-proxy-agent-2.2.1.tgz#51552970fa04d723e04c56d04178c3f92592bbc0"
+  dependencies:
+    agent-base "^4.1.0"
+    debug "^3.1.0"
+
 iconv-lite@^0.4.17:
   version "0.4.19"
   resolved "https://registry.yarnpkg.com/iconv-lite/-/iconv-lite-0.4.19.tgz#f7468f60135f5e5dad3399c0a81be9a1603a082b"
 
+ignore-walk@^3.0.1:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/ignore-walk/-/ignore-walk-3.0.1.tgz#a83e62e7d272ac0e3b551aaa82831a19b69f82f8"
+  dependencies:
+    minimatch "^3.0.4"
+
 ignore@^3.3.3:
   version "3.3.7"
   resolved "https://registry.yarnpkg.com/ignore/-/ignore-3.3.7.tgz#612289bfb3c220e186a58118618d5be8c1bab021"
@@ -1351,6 +1382,13 @@ js-yaml@^3.11.0, js-yaml@^3.2.7, js-yaml@^3.3.1, js-yaml@^3.6.1, js-yaml@^3.9.1:
     argparse "^1.0.7"
     esprima "^4.0.0"
 
+js-yaml@^3.12.0:
+  version "3.12.1"
+  resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.12.1.tgz#295c8632a18a23e054cf5c9d3cecafe678167600"
+  dependencies:
+    argparse "^1.0.7"
+    esprima "^4.0.0"
+
 jsbn@~0.1.0:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/jsbn/-/jsbn-0.1.1.tgz#a5e654c2e5a2deb5f201d96cefbca80c0ef2f513"
@@ -1657,6 +1695,10 @@ nise@^1.2.0:
     path-to-regexp "^1.7.0"
     text-encoding "^0.6.4"
 
+node-fetch@^2.2.0:
+  version "2.3.0"
+  resolved "https://registry.yarnpkg.com/node-fetch/-/node-fetch-2.3.0.tgz#1a1d940bbfb916a1d3e0219f037e89e71f8c5fa5"
+
 normalize-package-data@^2.3.2:
   version "2.4.0"
   resolved "https://registry.yarnpkg.com/normalize-package-data/-/normalize-package-data-2.4.0.tgz#12f95a307d58352075a04907b84ac8be98ac012f"
@@ -1982,7 +2024,7 @@ repeating@^2.0.0:
   dependencies:
     is-finite "^1.0.0"
 
-request@^2.79.0, request@^2.81.0:
+request@^2.79.0:
   version "2.86.0"
   resolved "https://registry.yarnpkg.com/request/-/request-2.86.0.tgz#2b9497f449b0a32654c081a5cf426bbfb5bf5b69"
   dependencies:
@@ -2437,6 +2479,14 @@ tap@12.0.1:
     write-file-atomic "^2.3.0"
     yapool "^1.0.0"
 
+teeny-request@^3.7.0:
+  version "3.11.3"
+  resolved "https://registry.yarnpkg.com/teeny-request/-/teeny-request-3.11.3.tgz#335c629f7645e5d6599362df2f3230c4cbc23a55"
+  dependencies:
+    https-proxy-agent "^2.2.1"
+    node-fetch "^2.2.0"
+    uuid "^3.3.2"
+
 test-exclude@^4.2.0:
   version "4.2.1"
   resolved "https://registry.yarnpkg.com/test-exclude/-/test-exclude-4.2.1.tgz#dfa222f03480bca69207ca728b37d74b45f724fa"
@@ -2577,7 +2627,7 @@ urix@^0.1.0:
   version "0.1.0"
   resolved "https://registry.yarnpkg.com/urix/-/urix-0.1.0.tgz#da937f7a62e21fec1fd18d49b35c2935067a6c72"
 
-urlgrey@0.4.4:
+urlgrey@^0.4.4:
   version "0.4.4"
   resolved "https://registry.yarnpkg.com/urlgrey/-/urlgrey-0.4.4.tgz#892fe95960805e85519f1cd4389f2cb4cbb7652f"
 
@@ -2595,6 +2645,10 @@ uuid@^3.1.0:
   version "3.2.1"
   resolved "https://registry.yarnpkg.com/uuid/-/uuid-3.2.1.tgz#12c528bb9d58d0b9265d9a2f6f0fe8be17ff1f14"
 
+uuid@^3.3.2:
+  version "3.3.2"
+  resolved "https://registry.yarnpkg.com/uuid/-/uuid-3.3.2.tgz#1b4af4955eb3077c501c23872fc6513811587131"
+
 validate-npm-package-license@^3.0.1:
   version "3.0.3"
   resolved "https://registry.yarnpkg.com/validate-npm-package-license/-/validate-npm-package-license-3.0.3.tgz#81643bcbef1bdfecd4623793dc4648948ba98338"