Remove leading ./ in compile_pip_requirements (#471)

examples/pip_install/requirements.txt

diff --git a/examples/pip_install/requirements.txt b/examples/pip_install/requirements.txt
index 6e8b232..78b0246 100644
--- a/examples/pip_install/requirements.txt
+++ b/examples/pip_install/requirements.txt
@@ -7,7 +7,7 @@
 boto3==1.14.51 \
     --hash=sha256:a6bdb808e948bd264af135af50efb76253e85732c451fa605b7a287faf022432 \
     --hash=sha256:f9dbccbcec916051c6588adbccae86547308ac4cd154f1eb7cf6422f0e391a71
-    # via -r ./requirements.in
+    # via -r requirements.in
 botocore==1.17.63 \
     --hash=sha256:40f13f6c9c29c307a9dc5982739e537ddce55b29787b90c3447b507e3283bcd6 \
     --hash=sha256:aa88eafc6295132f4bc606f1df32b3248e0fa611724c0a216aceda767948ac75

python/pip_install/pip_compile.py

diff --git a/python/pip_install/pip_compile.py b/python/pip_install/pip_compile.py
index 1d440a5..d5fbd83 100644
--- a/python/pip_install/pip_compile.py
+++ b/python/pip_install/pip_compile.py
@@ -13,7 +13,7 @@
     )
     sys.exit(1)
 
-requirements_in = sys.argv.pop(1)
+requirements_in = os.path.relpath(sys.argv.pop(1))
 requirements_txt = sys.argv.pop(1)
 update_target_name = sys.argv.pop(1)