Fix CI problems:

- Use the new MySQL 5.6 package on Travis.

- Do not cache `c:\sbt` at all on AppVeyor. Purging the cache when
  switching between branches (which install different sbt versions into
  different locations) doesn’t seem to work.

.travis.yml

@@ -1,5 +1,6 @@
language: scala
dist: trusty
sudo: required
language: scala
before_install:
# TZ needed for Oracle driver!
- export TZ=Asia/Kamchatka
@@ -22,7 +23,9 @@ addons:
    packages:
    - graphviz
    - python-sphinx
    - mysql-server
    - mysql-server-5.6
    - mysql-client-core-5.6
    - mysql-client-5.6
script:
- sbt -jvm-opts jvmopts.travis -Dslick.testkit-config=test-dbs/testkit.travis.conf clean +testAll
cache:

appveyor.yml

@@ -56,5 +56,4 @@ build_script:
test_script:
  - sbt testkit/test:test
cache:
  - C:\sbt\ -> appveyor.yml
  - C:\Users\appveyor\.ivy2