fixed yaml syntax

.travis.yml

@@ -1,13 +1,13 @@
 notifications:
-	email: false
+  email: false
 
 language: c
 
 before_script:
-	- wget https://launchpad.net/gcc-arm-embedded/4.8/4.8-2014-q2-update/+download/gcc-arm-none-eabi-4_8-2014q2-20140609-linux.tar.bz2 -O gcc-arm-none-eabi.tar.bz2
-	- mkdir -p gcc-arm-none-eabi
-	- tar xjf gcc-arm-none-eabi.tar.bz2 -C gcc-arm-none-eabi --strip-components 1
-	- export PATH=$PATH:$PWD/gcc-arm-none-eabi/bin/
+  - wget https://launchpad.net/gcc-arm-embedded/4.8/4.8-2014-q2-update/+download/gcc-arm-none-eabi-4_8-2014q2-20140609-linux.tar.bz2 -O gcc-arm-none-eabi.tar.bz2
+  - mkdir -p gcc-arm-none-eabi
+  - tar xjf gcc-arm-none-eabi.tar.bz2 -C gcc-arm-none-eabi --strip-components 1
+  - export PATH=$PATH:$PWD/gcc-arm-none-eabi/bin/
 
 script:
-	make
+  make