Add Clojure as supported language

[lucj]

Hi, as Clojure is a great functional language (of the lisp family, you know with lot of parenthesis), I was thinking of adding a template for it in OpenFaaS.

Some of the benefits of Clojure:

• based on Lisp
• relies on the standard JVM platform
• use JVM but do not have to write Java code :)
• real functional language with immutable data structures
• designed for concurrency
• more at https://clojure.org/about/rationale

When building an application, the project.clj file defines the dependencies. It contains metadata and deps. For instance:

(defproject clojure-echo "0.1.0-SNAPSHOT"
  :description "echo function"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [[org.clojure/clojure "1.7.0"]]
  :main ^:skip-aot clojure-echo.core
  :target-path "target/%s"
  :profiles {:uberjar {:aot :all}})

Those dependencies are installed with 'lein deps'.

To benefit from the cache when building the image, the deps can be downloaded and installed beforehand. The application can then be built and run as a jar.

[alexellis]

Thank you for taking time to write out a proposal @lucj. Please could you start by creating a sample function over in the main OpenFaaS repo?

https://github.com/alexellis/faas/blob/master/sample-functions/

Please also see - #86 and #85

Alex

[lucj]

faas-reverse-geocoding function added to https://github.com/faas-and-furious