Ignore failure to import fcntl

Fixes #190

Author: ddemidov

ev3dev/core.py

@@ -41,7 +41,6 @@
 import io
 import fnmatch
 import numbers
-import fcntl
 import array
 import mmap
 import ctypes
@@ -52,6 +51,14 @@
 from struct import pack, unpack
 from subprocess import Popen
 
+try:
+    # This is a linux-specific module.
+    # It is required by the Button() class, but failure to import it may be
+    # safely ignored if one just needs to run API tests on Windows.
+    import fcntl
+except ImportError:
+    print("WARNING: Failed to import fcntl. Button class will be unuseable!")
+
 INPUT_AUTO = ''
 OUTPUT_AUTO = ''