add apidocjs docker task image build

dockerfiles/tasks/apidocjs/Dockerfile

@@ -0,0 +1,13 @@
+# Using alpine linux for small image
+# - http://gliderlabs.viewdocs.io/docker-alpine/
+FROM alpine:3.4
+MAINTAINER Richard Morgan <r_morgan@sympatico.ca>
+LABEL version=2.0
+
+# install system packages
+RUN apk --no-cache add \
+  nodejs \
+ && npm install apidoc -g
+
+WORKDIR /src
+