Merge pull request Arduino-IRremote#306 from ivankravets/patch-4

Cache PlatformIO packages using Travis CI container-based infrastructure

Author: z3t0

.travis.yml

@@ -1,6 +1,12 @@
 language: python
 python:
     - "2.7"
+    
+# Cache PlatformIO packages using Travis CI container-based infrastructure
+sudo: false
+cache:
+    directories:
+        - "~/.platformio"    
 
 env:
     - PLATFORMIO_CI_SRC=examples/AiwaRCT501SendDemo PLATFORMIO_BUILD_FLAGS="-DSEND_AIWA_RC_T501"
@@ -16,7 +22,7 @@ env:
     - PLATFORMIO_CI_SRC=examples/IRremoteInfo 
 
 install:
-    - python -c "$(curl -fsSL https://raw.githubusercontent.com/platformio/platformio/master/scripts/get-platformio.py)"
+    - pip install -U platformio
 
 script:
     - platformio ci --lib="." --board=uno --board=leonardo --board=pro16MHzatmega168