Update "grape" gem

Gemfile

@@ -55,8 +55,7 @@ gem 'liquid',           '3.0.6'   # for email templates
 gem 'cancancan', '1.11.0' # autharization
 gem 'devise',    '4.4.3'  # authenitcation
 
-# rest api
-gem 'grape',    '0.12.0'
+gem 'grape'
 gem 'hashie-forbidden_attributes', '0.1.1' # For grape, https://github.com/ruby-grape/grape/tree/v0.12.0#rails
 gem 'jbuilder', '2.2.16'  # json api
 

Gemfile.lock

@@ -186,15 +186,12 @@ GEM
       thor (~> 0.14)
     globalid (0.4.1)
       activesupport (>= 4.2.0)
-    grape (0.12.0)
+    grape (1.0.3)
       activesupport
       builder
-      hashie (>= 2.1.0)
-      multi_json (>= 1.3.2)
-      multi_xml (>= 0.5.2)
+      mustermann-grape (~> 1.0.0)
       rack (>= 1.3.0)
       rack-accept
-      rack-mount
       virtus (>= 1.0.0)
     gyoku (1.3.1)
       builder (>= 2.1.2)
@@ -207,7 +204,7 @@ GEM
       html2haml (>= 1.0.1)
       railties (>= 4.0.1)
     hashdiff (0.3.7)
-    hashie (3.5.5)
+    hashie (3.5.7)
     hashie-forbidden_attributes (0.1.1)
       hashie (>= 3.0)
     hpricot (0.8.6)
@@ -268,8 +265,10 @@ GEM
       monetize (~> 1.6.0)
       money (~> 6.8.1)
       railties (>= 3.0)
-    multi_json (1.12.1)
-    multi_xml (0.6.0)
+    multi_json (1.13.1)
+    mustermann (1.0.2)
+    mustermann-grape (1.0.0)
+      mustermann (~> 1.0.0)
     netrc (0.11.0)
     nokogiri (1.8.4)
       mini_portile2 (~> 2.3.0)
@@ -294,8 +293,6 @@ GEM
     rack (1.6.10)
     rack-accept (0.4.5)
       rack (>= 0.4)
-    rack-mount (0.8.3)
-      rack (>= 1.0.0)
     rack-protection (1.5.5)
       rack
     rack-test (0.6.3)
@@ -472,7 +469,7 @@ DEPENDENCIES
   epp-xml (= 1.1.0)!
   factory_bot_rails
   figaro (= 1.1.1)
-  grape (= 0.12.0)
+  grape
   haml-rails (= 0.9.0)
   hashie-forbidden_attributes (= 0.1.1)
   html2haml (= 2.1.0)