Added minimal build+size reporting to CI based on static config

.travis.yml

@@ -208,6 +208,31 @@ jobs:
     script:
       - make test TFLAGS+="-k --valgrind"
 
+  # test minimal compilation using static configs
+  - stage: test
+    env:
+      - NAME=littlefs-minimal
+      - CC="arm-linux-gnueabi-gcc --static -mthumb"
+      - CFLAGS="-Werror
+            -DLFS_STATICCFG -DLFS_FILE_STATICCFG
+            -DLFS_READ_SIZE=16
+            -DLFS_PROG_SIZE=16
+            -DLFS_BLOCK_SIZE=512
+            -DLFS_BLOCK_COUNT=1024
+            -DLFS_BLOCK_CYCLES=-1
+            -DLFS_CACHE_SIZE=64
+            -DLFS_LOOKAHEAD_SIZE=16
+            -DLFS_NO_ASSERT -DLFS_NO_DEBUG -DLFS_NO_WARN -DLFS_NO_ERROR"
+    if: branch !~ -prefix$
+    install:
+      - *install-common
+      - sudo apt-get install
+            gcc-arm-linux-gnueabi
+            libc6-dev-armel-cross
+      - arm-linux-gnueabi-gcc --version
+    # report-size will compile littlefs and report the size
+    script: [*report-size]
+
   # self-host with littlefs-fuse for fuzz test
   - stage: test
     env: