Instruction with keyword that spans multiple lines raises a false linting error

[rcjsuen]

FROM alpine
FR\

OM scratch

$ docker build .
Sending build context to Docker daemon  38.15MB
[WARNING]: Empty continuation line found in:
    FROM scratch
[WARNING]: Empty continuation lines will become errors in a future release.
Step 1/2 : FROM alpine
 ---> e7d92cdc71fe
Step 2/2 : FROM scratch
 ---> 
No image was generated. Is your Dockerfile empty?
[node1] (local) root@192.168.0.23 ~

$ docker run -v `pwd`/Dockerfile:/Dockerfile rcjsuen/dockerfile-utils lint /Dockerfile

Line: 2
FR\
^^
Error: Unknown instruction: FR

Line: 4
OM scratch
^^
Error: Unknown instruction: OM