scripts: restore install_build_tools.sh

[MaxMustermann2]

With #4427, the protofiles are generated using a Docker image and thus protoc related binaries are not required. However, mockgen and golangci-lint are still being used by our Travis build. This change restores the file that installs them, and removes protoc related files from the list of installations.

[MaxMustermann2]

The Dockerfile that runs in our Travis CI clones the main branch of this repo. Since the script in question has been removed from that branch, the Travis CI fails with error 127 (which indicates file not found).

To test this change, I locally modified the Dockerfile to clone my fork of harmony and checkout the branch restore-build-tools. With this change, the Travis RPC test passes.

diff --git a/localnet/Dockerfile b/localnet/Dockerfile
index cac0b75..5796c12 100644
--- a/localnet/Dockerfile
+++ b/localnet/Dockerfile
@@ -12,7 +12,7 @@ RUN apt upgrade -y > /dev/null 2>1
 RUN apt update -y > /dev/null 2>1
 RUN apt install -y unzip libgmp-dev libssl-dev curl git jq make gcc g++ bash sudo python3 python3-pip > /dev/null 2>1
 
-RUN git clone https://github.com/harmony-one/harmony.git > /dev/null 2>1 \
+RUN git clone https://github.com/MaxMustermann2/harmony.git > /dev/null 2>1 \
     && git clone https://github.com/harmony-one/bls.git > /dev/null 2>1 \
     && git clone https://github.com/harmony-one/mcl.git > /dev/null 2>1
 
@@ -23,7 +23,7 @@ RUN git config --global --add safe.directory $GOPATH/src/github.com/harmony-one/
     && git config --global --add safe.directory $GOPATH/src/github.com/harmony-one/mcl > /dev/null 2>1
 
 # Build to fetch all dependencies for faster test builds
-RUN cd harmony > /dev/null 2>1 && go mod tidy > /dev/null 2>1 && go get github.com/pborman/uuid > /dev/null 2>1 && go get github.com/rjeczalik/notify > /dev/null 2>1 \
+RUN cd harmony > /dev/null 2>1 && git checkout restore-build-tools && go mod tidy > /dev/null 2>1 && go get github.com/pborman/uuid > /dev/null 2>1 && go get github.com/rjeczalik/notify > /dev/null 2>1 \
     && go get github.com/cespare/cp > /dev/null 2>1 && go get github.com/libp2p/go-libp2p-crypto > /dev/null 2>1 && go get github.com/kr/pretty > /dev/null 2>1 \
     && go get github.com/kr/text > /dev/null 2>1 && go get gopkg.in/check.v1 > /dev/null 2>1 && bash scripts/install_build_tools.sh > /dev/null 2>1 && make > /dev/null 2>1
 RUN rm -rf harmony

As a reminder the > /dev/null 2>1 is added after each command to pacify the log length limits imposed by Travis.

The RPC check then passes:

=========================== short test summary info ============================
SKIPPED [1] rpc_tests/test_staking.py:933: This test is flaky and needs to be fixed
SKIPPED [1] rpc_tests/test_staking.py:1210: This test is flaky and needs to be fixed
SKIPPED [1] rpc_tests/test_staking.py:1249: This test is flaky and needs to be fixed
================== 84 passed, 3 skipped in 132.51s (0:02:12) ===================

=== FINISHED RPC TESTS ===

Passed RPC tests

[ONECasey]

Lets get this PR and the hard fork data into the next push to main.