Update our build matrix

Looks like we hit a big breaking change with the latest yesod major
version. I took a look at the CPP needed and it wouldn't be worth
it. This forces us to cut lts-10 and older loose. I've also allowed
nightly tests to fail since there are a lot of dependencies that are
trailing behind.

.travis.yml

@@ -25,10 +25,10 @@ cache:
 
 matrix:
   include:
-    # last 3 LTS and nightly
-    - env: STACKARGS="--resolver=lts-8"
-    - env: STACKARGS="--resolver=lts-9"
-    - env: STACKARGS="--resolver=lts-10"
+    - env: STACKARGS="--resolver=lts-11"
+    - env: STACKARGS="--resolver=lts-12"
+    - env: STACKARGS="--resolver=nightly"
+  allow_failures:
     - env: STACKARGS="--resolver=nightly"
 
 before_install:

stack.yaml

@@ -1,4 +1,4 @@
-resolver: lts-11.9
+resolver: lts-12.13
 packages:
   - serversession
   - serversession-backend-acid-state
@@ -25,13 +25,8 @@ flags:
     lib-Werror: true
 extra-deps:
   - acid-state-0.14.3
-  # for lts 9, 10
-  # - snap-1.1.0.0
-  # - snap-core-1.0.3.1
-  # - snap-server-1.0.3.3
-  # - heist-1.0.1.2
-  # - map-syntax-0.2.0.2
-  # - xmlhtml-0.2.5.2
-  # for lts-8
-  # - blaze-html-0.9.0.1
-  # - blaze-markup-0.8.2.0
+  - snap-1.1.1.0
+  - heist-1.1
+  - map-syntax-0.3
+  - pwstore-fast-2.4.4
+  - xmlhtml-0.2.5.2