Modify icefall/__init__.py. (#287)

* Modify icefall/__init__.py to import common functions defined in icefall/utils.py.

* Modify icefall/__init__.py and .flake8.

.flake8

@@ -13,4 +13,5 @@ per-file-ignores =
 exclude =
   .git,
   **/data/**,
-  icefall/shared/make_kn_lm.py
+  icefall/shared/make_kn_lm.py,
+  icefall/__init__.py

icefall/__init__.py

@@ -0,0 +1,24 @@
+from .utils import (
+    AttributeDict,
+    MetricsTracker,
+    add_eos,
+    add_sos,
+    concat,
+    encode_supervisions,
+    get_alignments,
+    get_executor,
+    get_texts,
+    l1_norm,
+    l2_norm,
+    linf_norm,
+    load_alignments,
+    make_pad_mask,
+    measure_gradient_norms,
+    measure_weight_norms,
+    optim_step_and_measure_param_change,
+    save_alignments,
+    setup_logger,
+    store_transcripts,
+    str2bool,
+    write_error_stats,
+)