Travis does the developer build and runs {unit,spec} tests. (#84)

Travis does the developer build and runs {unit,spec} tests.

* Add the dependencies from `build/dev.sh ubuntu-deps` and `test/spec.sh install-shells` as packages for container (according to travis documentation).
* Run necessary script `test/spec.sh link-busy-box-ash` before installation.
* Create `_tmp` directory that is used by tests.

Although it's possible to install the dependencies through the script `build/dev.sh ubuntu-deps`, that'd imply that the integration has to be done using a VM instead of a container (because the script uses sudo).

.travis.yml

@@ -2,11 +2,37 @@ language: python
cache: pip
python:
    - 2.7

addons:
    apt:
        packages:
            # build/dev.sh ubuntu-deps
            - python-dev
            - gawk
            - time
            - libreadline-dev
            # test/spec.sh install-shells
            - busybox-static
            - mksh
            - zsh

before_install:
    - test/spec.sh link-busybox-ash
    - mkdir -p _tmp

install:
    #- pip install -r requirements.txt
    # - pip install -r requirements.txt
    - pip install flake8  # pytest  # add another testing frameworks later
    - build/dev.sh minimal

script:
    - test/lint.sh travis
    # Unit tests
    - test/unit.sh all
    # Spec tests
    - test/spec.sh smoke
    - test/spec.sh all

notifications:
    on_success: change
    on_failure: change  # `always` will be the setting once code changes slow down

README.md

@@ -1,6 +1,9 @@
Oil
===

[![Build
Status](https://travis-ci.org/oilshell/oil.svg)](https://travis-ci.org/oilshell/oil)

Oil is a new Unix shell.  [Why Create a New Unix Shell?][why]

[why]: http://www.oilshell.org/blog/2018/01/28.html
@@ -70,7 +73,7 @@ Directory Structure
    test/             # Test automation
      unit.sh         ## Types of test runner: unit, spec, wild, smoke
      spec.sh
      wild.sh        
      wild.sh
      smoke.sh
      sh_spec.py      # shell spec test framework
    spec/             # spec test cases
@@ -121,7 +124,7 @@ Directory Structure
          ...
        web/          # Static files, copy of $REPO_ROOT/web
          table/
      


    # Dev Docs