Updated BuildServices (asciidoc)

BuildServices.asciidoc

@@ -23,6 +23,44 @@ nim c -r <mytest.nim>
 
 Be aware that the available .deb packages will change over time.
 
+### Using CircleCI 2.0 with choosenim
+
+choosenim allow picking fixed Nim versions or updating to the last stable or devel version
+
+Use this .circleci/config.yml
+
+---
+version: 2
+jobs:
+  build:
+    machine: true
+    steps:
+      - run: echo 'export PATH=~/.nimble/bin:$PATH' >> $BASH_ENV
+      - checkout
+      # Reuse cached Nim compiler
+      - restore_cache:
+          key: compiler-0002
+      - run:
+          command: |
+            if [ -f ~/.nimble/bin/choosenim ]; then
+              echo "Updating Nim using choosenim"
+              choosenim stable
+            else
+              echo "Installing choosenim and Nim"
+              wget https://raw.githubusercontent.com/dom96/choosenim/master/scripts/choosenim-unix-init.sh
+              sh choosenim-unix-init.sh -y
+            fi
+      - save_cache:
+          key: compiler-0002
+          paths:
+            - ~/.nimble
+            - ~/.choosenim
+      - run:
+          command: |
+            nimble build -y
+            # add here your tests
+---
+
 ## Building Nim projects on Circle CI v2.0 using Nim Devel
 
 Create .circleci/config.yml as: