Make API Codegen Work on Linux

[ckadner]

Code Changes:

• Use a platform-specific gsed alias in api/codegen.sh script
• Delete duplicated api/add_license_headers.sh script
• Move existing helper scripts from /hack to /tools
• Remove .travis.yml and git_push.sh from API code generation

Resolves #254

Additional Information:

Use Docker for testing using Linux/Ubuntu for developers using macOS:

• Create a Dockerfile like this:

FROM ubuntu:latest

RUN apt-get -y update
RUN apt-get -y install git
RUN apt-get -y install make
RUN apt-get -y install curl
RUN apt-get -y install wget

ENV DEBIAN_FRONTEND=noninteractive
RUN apt-get -y install default-jre-headless

RUN apt-get clean && rm -rf /var/lib/apt/lists/*

• Build the image and run the container:

docker build -t ubuntu-make-curl-git-java .

docker run -it ubuntu-make-curl-git-java /bin/bash

• Inside the container, run the api/codegen.sh script:

git clone https://github.com/ckadner/mlx.git
cd mlx
git checkout fix_codegen_on_linux
./api/codegen.sh
git status

Note:: the api/generate_code.sh script will only work after this PR got merged, since it relies on comparing current codegen results with those of a previous (latest) commit from main (which will not yet have the fix).

[mlx-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ckadner

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[ckadner]

@BluThaitanium -- this PR uses the same fix you provided last week in PR #250 -- Please review when you get a chance. Thanks!

[JAulet]

/lgtm

[ckadner]

Thanks @JAulet