[GH-54] Fix golang releases without patch version not being installed

This workarounds two sides' choices.

First Golang does not release major versions,
 e.g `1.11.0` with the patch version of `0`.

Second goenv only adds installable definitions
 with patch version as per semantic versioning by the book (arguably).

The solution here is when provided with a install definition such as `1.11`
 to add a patch version of `0` automatically and the result will be a search
 for install definition `1.11.0`.

CHANGELOG.md

@@ -53,6 +53,10 @@ Change line format:
 
 ## Unreleased (master)
 
+### Fixed
+
+* Golang releases without patch version not being installed ; Ref: https://github.com/syndbg/goenv/pull/75
+
 ## 2.0.0beta8
 
 ### Added

plugins/go-build/bin/go-build

@@ -775,6 +775,12 @@ done
 [ "${#ARGUMENTS[@]}" -eq 2 ] || usage 1 >&2
 
 DEFINITION_PATH="${ARGUMENTS[0]}"
+# NOTE: Try to capture semantic versions such as `1.11` which don't have a patch version.
+# A patch version of 0 will be added, e.g they'll be changed to `1.11.0`.
+if grep -q -E "^[0-9]+\.[0-9]+(\s*)$" <<< ${DEFINITION_PATH}; then
+  DEFINITION_PATH="${DEFINITION_PATH}.0"
+fi
+
 if [ -z "$DEFINITION_PATH" ]; then
   usage 1 >&2
 elif [ ! -f "$DEFINITION_PATH" ]; then