Revert to Delve 1.3.1 (#36)

Author: briandealwis

go/Dockerfile

@@ -1,8 +1,8 @@
 FROM golang:1.14.1 as delve
-RUN curl --location --output delve-1.4.0.tar.gz https://github.com/go-delve/delve/archive/v1.4.0.tar.gz \
-  && tar xzf delve-1.4.0.tar.gz
+RUN curl --location --output delve-1.3.1.tar.gz https://github.com/go-delve/delve/archive/v1.3.1.tar.gz \
+  && tar xzf delve-1.3.1.tar.gz
 # Produce an as-static-as-possible dlv binary to work on musl and glibc
-RUN cd delve-1.4.0 && CGO_ENABLED=0 go build -o /go/dlv -ldflags '-extldflags "-static"' ./cmd/dlv/
+RUN cd delve-1.3.1 && CGO_ENABLED=0 go build -o /go/dlv -ldflags '-extldflags "-static"' ./cmd/dlv/
 
 # Now populate the duct-tape image with the language runtime debugging support files
 # The debian image is about 95MB bigger