Google::Protobuf::Map#inspect should be consistent with Hash#inspect

ruby/ext/google/protobuf_c/map.c

@@ -683,7 +683,7 @@ VALUE Map_inspect(VALUE _self) {
       first = false;
     }
     str = rb_str_append(str, rb_funcall(key, inspect_sym, 0));
-    str = rb_str_cat2(str, " => ");
+    str = rb_str_cat2(str, "=>");
     str = rb_str_append(str, rb_funcall(value, inspect_sym, 0));
   }
 

ruby/tests/basic.rb

@@ -391,7 +391,7 @@ module BasicTest
       # We only assert on inspect value when there is one map entry because the
       # order in which elements appear is unspecified (depends on the internal
       # hash function). We don't want a brittle test.
-      assert m.inspect == "{\"jkl;\" => 42}"
+      assert m.inspect == "{\"jkl;\"=>42}"
 
       assert m.keys == ["jkl;"]
       assert m.values == [42]