Update Android builder (Beta Version)

as discussed with @joshk

ref travis-ci/travis-ci#1395
Minor: remove a trailing space
Android: don't overkill with should_not checks
Merge pull request #238 from travis-ci/android-beta

Update Android builder (Beta Version)
Expose tag as TRAVIS_TAG.

Fixes travis-ci/travis-ci#1674
env: make TRAVIS_OS_NAME pull from config, not job

This is probably the cause of travis-ci/travis-ci#2205.
spec: move the 'os' variable from job to config

This fixes the broken spec from the previous commit.
Add #if_file_exists and #elif_file_exists

A common use case of "if" is to test if a file exists at the
indicated path.
This is now extracted.

.create method for the conditional is now put in the Conditional
class, so that Elif can use it, too.
Use if_file_exists and elif_file_exists
Fix syntax error in specs
Android: use gradle build instead of gradle check

ref #238 and #142
Fix spec's expected number of TRAVIS_* environment variables

TRAVI_OS_NAME is no longer tested here
Merge pull request #239 from travis-ci/gc-android-gradle-defaults

Android: use gradle build instead of gradle check

Actually, I'll go ahead and merge it. It should be fine here.
we don't need to 'fix ssl' anymore
Set TERM to 'dumb' for JVM builds
Merge pull request #240 from travis-ci/ha-gh-travis-ci-2275

Set TERM to 'dumb' for JVM builds
Set TERM to 'dumb' when Gradle config is detected

There are following issues with #240 (dfe2bfc):

- Android builder does not export TERM=dumb (common parts are in jdk.rb,
  not jvm.rb)
- TERM=dumb would be exported for all JVM languages, even if not built
  with Gradle.
Merge pull request #241 from travis-ci/gh-2275-gradle-change

Set TERM to 'dumb' when Gradle config is detected
Merge branch 'master' into ha-feature-windows

Conflicts:
	lib/travis/build/script/android.rb