build: upgrade to go 1.17 and dependencies

vendor/gocv.io/x/gocv/Dockerfile-test

@@ -0,0 +1,19 @@
+# To build:
+#   docker build -f Dockerfile-test -t gocv-test .
+#
+# To run tests:
+#   xhost +
+#   docker run -it --rm -e DISPLAY=$DISPLAY -v /tmp/.X11-unix:/tmp/.X11-unix gocv-test
+#   xhost -
+#
+FROM gocv/opencv:4.5.3 AS gocv-test
+
+ENV GOPATH /go
+
+COPY . /go/src/gocv.io/x/gocv/
+
+WORKDIR /go/src/gocv.io/x/gocv
+
+RUN go get -u github.com/rakyll/gotest
+
+ENTRYPOINT ["gotest", "-v", ".", "./contrib/..."]