Switch coverage host from coveralls -> codecov

Coveralls seems incapable of cleanly handling parallel results.

Gemfile.lock

@@ -122,6 +122,10 @@ GEM
       aws_cf_signer
       rest-client
     cocoon (1.2.6)
+    codecov (0.1.10)
+      json
+      simplecov
+      url
     coderay (1.1.1)
     concurrent-ruby (1.0.5)
     countable-rails (0.0.1)
@@ -132,12 +136,6 @@ GEM
     country_select (2.5.2)
       countries (~> 1.2.0)
       sort_alphabetical (~> 1.0)
-    coveralls (0.8.21)
-      json (>= 1.8, < 3)
-      simplecov (~> 0.14.1)
-      term-ansicolor (~> 1.3)
-      thor (~> 0.19.4)
-      tins (~> 1.6)
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
     crass (1.0.3)
@@ -161,7 +159,7 @@ GEM
     devise_ichain_authenticatable (0.3.1)
       devise (>= 2.2)
     diff-lcs (1.3)
-    docile (1.1.5)
+    docile (1.3.0)
     domain_name (0.5.20160310)
       unf (>= 0.0.5, < 1.0.0)
     dotenv (2.2.1)
@@ -497,8 +495,8 @@ GEM
     shellany (0.0.1)
     shoulda-matchers (2.8.0)
       activesupport (>= 3.0.0)
-    simplecov (0.14.1)
-      docile (~> 1.1.0)
+    simplecov (0.16.1)
+      docile (~> 1.1)
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
@@ -525,13 +523,10 @@ GEM
       multi_json (>= 1.0.0)
       stripe (>= 1.31.0, <= 1.43)
     sysexits (1.2.0)
-    term-ansicolor (1.6.0)
-      tins (~> 1.0)
     thor (0.19.4)
     thread_safe (0.3.6)
     tilt (1.4.1)
     timecop (0.7.1)
-    tins (1.16.3)
     transitions (0.1.12)
     ttfunk (1.1.1)
     turbolinks (5.1.0)
@@ -548,6 +543,7 @@ GEM
     unicode_utils (1.4.0)
     unobtrusive_flash (3.1.0)
       railties
+    url (0.3.2)
     user_agent_parser (2.4.0)
     uuidtools (2.1.5)
     warden (1.2.4)
@@ -596,9 +592,9 @@ DEPENDENCIES
   climate_control
   cloudinary
   cocoon
+  codecov
   countable-rails (~> 0.0.1)
   country_select
-  coveralls
   daemons
   dalli
   database_cleaner