Remove gr dependencies

Gemfile.lock

@@ -15,12 +15,9 @@ GEM
     daemons (1.4.1)
     et-orbi (1.2.6)
       tzinfo
-    fiddle (1.1.0)
     fugit (1.5.2)
       et-orbi (~> 1.1, >= 1.1.8)
       raabro (~> 1.4)
-    gr-plot (0.0.1)
-      ruby-gr
     gruff (0.19.0)
       histogram
       rmagick (>= 4.2)
@@ -37,14 +34,9 @@ GEM
       mini_portile2 (~> 2.7.0)
       racc (~> 1.4)
     numo-narray (0.9.2.1)
-    pkg-config (1.4.9)
     raabro (1.4.0)
     racc (1.6.0)
     rmagick (5.0.0)
-    ruby-gr (0.66.0.0)
-      fiddle
-      numo-narray
-      pkg-config
     rufus-scheduler (3.8.0)
       fugit (~> 1.1, >= 1.1.6)
     serialport (1.3.2)
@@ -58,15 +50,12 @@ PLATFORMS
 DEPENDENCIES
   activerecord
   daemons
-  gr-plot
   gruff
-  histogram
   i18n
   mail
   mysql2
   nokogiri
   numo-narray
-  ruby-gr
   rufus-scheduler
   serialport
   state_pattern