scala 2.12.10 is default version, closes #703 (#1054)

* scala 2.12.10 is default version, closes #703

* specs2 matcher to try catch

* default 2.12.11 (latest)

* update golden coverage file

Author: ittaiz

README.md

@@ -126,18 +126,18 @@ Please check [coverage.md](docs/coverage.md) for more details on coverage suppor
 Rules scala supports the last two released minor versions for each of Scala 2.11 and 2.12.
 Previous minor versions may work but are supported only on a best effort basis.
 
-By default `Scala 2.11.12` is used and to use another version you need to
+By default `Scala 2.12.10` is used and to use another version you need to
 specify it when calling `scala_repositories`. `scala_repositories` takes a tuple `(scala_version, scala_version_jar_shas)`
 as a parameter where `scala_version` is the scala version and `scala_version_jar_shas` is a `dict` with
 `sha256` hashes for the maven artifacts `scala_compiler`, `scala_library`, and `scala_reflect`:
 
 ```python
 scala_repositories((
-    "2.12.10",
+    "2.11.12",
     {
-       "scala_compiler": "cedc3b9c39d215a9a3ffc0cc75a1d784b51e9edc7f13051a1b4ad5ae22cfbc0c",
-       "scala_library": "0a57044d10895f8d3dd66ad4286891f607169d948845ac51e17b4c1cf0ab569d",
-       "scala_reflect": "56b609e1bab9144fb51525bfa01ccd72028154fc40a58685a1e9adcbe7835730"
+        "scala_compiler": "3e892546b72ab547cb77de4d840bcfd05c853e73390fed7370a8f19acb0735a0",
+        "scala_library": "0b3d6fd42958ee98715ba2ec5fe221f4ca1e694d7c981b0ae0cd68e97baf6dce",
+        "scala_reflect": "6ba385b450a6311a15c918cf8688b9af9327c6104f0ecbd35933cfcd3095fe04",
     }
 ))
 ```

WORKSPACE

@@ -63,7 +63,7 @@ jvm_maven_import_external(
         "com.twitter:scalding-date:0.17.0",
         default_scala_major_version(),
     ),
-    artifact_sha256 = "bf743cd6d224a4568d6486a2b794143e23145d2afd7a1d2de412d49e45bdb308",
+    artifact_sha256 = "973a7198121cc8dac9eeb3f325c93c497fe3b682f68ba56e34c1b210af7b15b3",
     server_urls = MAVEN_SERVER_URLS,
 )
 
@@ -74,18 +74,18 @@ jvm_maven_import_external(
         "org.typelevel:cats-core:0.9.0",
         default_scala_major_version(),
     ),
-    artifact_sha256 = "3fda7a27114b0d178107ace5c2cf04e91e9951810690421768e65038999ffca5",
+    artifact_sha256 = "3ca705cba9dc0632e60477d80779006f8c636c0e2e229dda3410a0c314c1ea1d",
     server_urls = MAVEN_SERVER_URLS,
 )
 
 # test of a plugin
 jvm_maven_import_external(
     name = "org_psywerx_hairyfotr__linter",
     artifact = scala_mvn_artifact(
-        "org.psywerx.hairyfotr:linter:0.1.13",
+        "org.psywerx.hairyfotr:linter:0.1.17",
         default_scala_major_version(),
     ),
-    artifact_sha256 = "9444dd78684c0cc89d070af0f5ca3f3ae7d56b2a4d7ac1c038f8218ad4d66fad",
+    artifact_sha256 = "59becd7883613064842b3a62f84315b02457dc439f42ef62e3c80408393c905b",
     server_urls = MAVEN_SERVER_URLS,
 )
 
@@ -243,7 +243,7 @@ scala_maven_import_external(
         "org.spire-math:kind-projector:0.9.10",
         default_scala_major_version(),
     ),
-    artifact_sha256 = "897460d4488b7dd6ac9198937d6417b36cc6ec8ab3693fdf2c532652f26c4373",
+    artifact_sha256 = "36aca2493302e2c037328107a121cda1d28bf9119fbc04fb47ea1ff9bce3c03f",
     fetch_sources = False,
     licenses = ["notice"],
     server_urls = MAVEN_SERVER_URLS,

scala/scala_cross_version.bzl

@@ -22,13 +22,13 @@ resolution."""
 
 def default_scala_version():
     """return the scala version for use in maven coordinates"""
-    return "2.11.12"
+    return "2.12.11"
 
 def default_scala_version_jar_shas():
     return {
-        "scala_compiler": "3e892546b72ab547cb77de4d840bcfd05c853e73390fed7370a8f19acb0735a0",
-        "scala_library": "0b3d6fd42958ee98715ba2ec5fe221f4ca1e694d7c981b0ae0cd68e97baf6dce",
-        "scala_reflect": "6ba385b450a6311a15c918cf8688b9af9327c6104f0ecbd35933cfcd3095fe04",
+        "scala_compiler": "e901937dbeeae1715b231a7cfcd547a10d5bbf0dfb9d52d2886eae18b4d62ab6",
+        "scala_library": "dbfe77a3fc7a16c0c7cb6cb2b91fecec5438f2803112a744cb1b187926a138be",
+        "scala_reflect": "5f9e156aeba45ef2c4d24b303405db259082739015190b3b334811843bd90d6a",
     }
 
 def default_maven_server_urls():