Osx build linker args (#330)

* Add linker flags for macOS to ensure proper linking with macOS libpython library

* Include custom build.rs script

* Add apache license to build.rs

* Add apache license v2

Author: jdye64

.cargo/config.toml

@@ -0,0 +1,12 @@
+[target.x86_64-apple-darwin]
+rustflags = [
+  "-C", "link-arg=-undefined",
+  "-C", "link-arg=dynamic_lookup",
+]
+
+[target.aarch64-apple-darwin]
+rustflags = [
+  "-C", "link-arg=-undefined",
+  "-C", "link-arg=dynamic_lookup",
+]
+

Cargo.lock

@@ -52,6 +52,9 @@ regex-syntax = "0.6.28"
 syn = "2.0.11"
 url = "2.2"
 
+[build-dependencies]
+pyo3-build-config = "0.18.3"
+
 [lib]
 name = "datafusion_python"
 crate-type = ["cdylib", "rlib"]