chore(circle): Add circle.yml

Author: DanSnow

circle.yml

@@ -0,0 +1,20 @@
+machine:
+  environment:
+    CRYSTAL_VERSION: "0.20.1"
+    PATH: "${PATH}:${HOME}/.crystal/bin"
+    CRYSTAL_URL: "https://github.com/crystal-lang/crystal/releases/download/${CRYSTAL_VERSION}/crystal-${CRYSTAL_VERSION}-1-linux-x86_64.tar.gz"
+dependencies:
+  cache_directories:
+    - ".crystal"
+  pre:
+    - |
+      if [[ ! -e .crystal/bin/crystal || $(crystal --version | grep -P -o '\d+\.\d+\.\d+') != "${CRYSTAL_VERSION}" ]]; then
+        mkdir .crystal
+        wget "${CRYSTAL_URL}" -O crystal.tar.gz &&\
+        tar -zxvf crystal.tar.gz -C .crystal --strip-components=1
+      fi
+  override:
+    - crystal deps
+test:
+  override:
+    - crystal spec