[luci-go] remove isolate.sha1

isolate is taken from CIPD now

Change-Id: I6fb13fd6ae4bfda4ab9d414284c37cfc2dfc0e91
Reviewed-on: https://chromium-review.googlesource.com/c/1475144
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
Commit-Queue: Marc-Antoine Ruel <maruel@chromium.org>
Reviewed-by: Marc-Antoine Ruel <maruel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#632600}
diff --git a/tools/luci-go/.gitignore b/tools/luci-go/.gitignore
index 2934681..afa2b1a 100644
--- a/tools/luci-go/.gitignore
+++ b/tools/luci-go/.gitignore
@@ -2,9 +2,6 @@
 /isolate.exe
 /isolated
 /isolated.exe
-/linux64/isolate
-/mac64/isolate
 /swarming
 /swarming.exe
-/win64/isolate.exe
 .versions
diff --git a/tools/luci-go/linux64/isolate.sha1 b/tools/luci-go/linux64/isolate.sha1
deleted file mode 100644
index 1610657..0000000
--- a/tools/luci-go/linux64/isolate.sha1
+++ /dev/null
@@ -1 +0,0 @@
-9734e966a14f9e26f86e38a020fcd7584248d285
diff --git a/tools/luci-go/mac64/isolate.sha1 b/tools/luci-go/mac64/isolate.sha1
deleted file mode 100644
index a61e43ab..0000000
--- a/tools/luci-go/mac64/isolate.sha1
+++ /dev/null
@@ -1 +0,0 @@
-18561de57e944d096521838b4e6cb49e0cc1df23
diff --git a/tools/luci-go/win64/isolate.exe.sha1 b/tools/luci-go/win64/isolate.exe.sha1
deleted file mode 100644
index 5ac52a0..0000000
--- a/tools/luci-go/win64/isolate.exe.sha1
+++ /dev/null
@@ -1 +0,0 @@
-af227603890ea1d8c082b5caf15e46a6bf060a2e