add config.py

Author: yztxwd

seqchromloader/config.py

@@ -0,0 +1,8 @@
+BIGWIG_BACKEND='pyBigWig'
+
+def set_bigwig_backend(backend):
+    global BIGWIG_BACKEND
+    
+    assert backend in ['pyBigWig', 'pybigtools'], "Backend options are pyBigWig or pybigtools!"
+
+    BIGWIG_BACKEND = backend