Lock pragmas to specific compiler version

[crypto-x-soldier]

Is your feature request related to a problem? Please describe.
One of the best practices is -> Contracts should be deployed with the same compiler version and flags that they have been tested the most with. Locking the pragma helps ensure that contracts do not accidentally get deployed.

https://consensys.github.io/smart-contract-best-practices/recommendations/#lock-pragmas-to-specific-compiler-version

Describe the solution you'd like
Update the following Solidity files to have a specific compiler lock.
Invest.sol
ERC20Helper.sol
ETHHelper.sol
Invest.sol
InvestorData.sol
MainCoinManager.sol
Manageable.sol
Migrations.sol
Pools.sol
PoolsData.sol
PozBenefit.sol

Wallet address
0xdD5F5feE4Db473ACa5A0b52EE459Abd35D098BEE