Added click and install

pysr/__main__.py

@@ -0,0 +1,4 @@
+from pysr._cli.main import cli as _cli
+
+if __name__ == '__main__':
+    _cli(prog_name="cli")

pysr/_cli/main.py

@@ -0,0 +1,16 @@
+import click
+from pysr.julia_helpers import install
+
+
+@click.group("cli")
+@click.pass_context
+def cli():
+    somevariable = "33"
+
+
+@cli.command("install")
+@click.option("--julia_project", default=None)
+@click.option("--quiet", default=False)
+@click.option("--precompile", default=None)
+def _install(julia_project, quiet, precompile):
+    install(julia_project, quiet, precompile)